# Oracle Automatic Storage Management Administrator's Guide This file contains the text from each Oracle Automatic Storage Management Administrator's Guide article landing page, release 19c. # Changes in This Release for Oracle Automatic Storage Management Administrators Guide ## Changes in Oracle Automatic Storage Management 19c Oracle ASM 19c introduces stricter permission checks for file-group and file-movement operations, enhanced SRVCTL management of ASM network resources, password-file metadata cache flushing, and ASMCMD improvements including optional password creation, forced replacement and format options, sparse-parent assignment, and file-group movement. It also adds parity-protected file support through `REDUNDANCY` settings for single or double parity. The `pwcreate` password option is deprecated, and Flex Cluster leaf nodes are desupported. Read More: [Changes in Oracle Automatic Storage Management 19c](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/changes-in-this-release-for-oracle-automatic-storage-management-administrators-guide/changes-in-oracle-automatic-storage-management-19c.html) ## Changes in Oracle ACFS and Oracle ADVM in Oracle ASM 19c Oracle ACFS 19c enhances diagnostic commands and views, supports online `fsck` analysis on Linux, and improves replication by allowing most replication commands for non-root ASM users and enabling remote standby termination. Deprecated capabilities include replication protocol version 1, ACFS encryption on Solaris and Windows, ACFS on Windows, ACFS Security (Vault), ACFS Auditing, ACFS on Member Clusters, and Cluster Domain Member Clusters; these may be removed in future releases, with ASM, DBFS, or Windows shares suggested as alternatives for Windows ACFS use. Read More: [Changes in Oracle ACFS and Oracle ADVM in Oracle ASM 19c](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/changes-in-this-release-for-oracle-automatic-storage-management-administrators-guide/changes-in-oracle-acfs-and-oracle-advm-in-oracle-asm-19c.html) # Part I Introduction Part I provides an overview of Oracle Automatic Storage Management (Oracle ASM), Oracle ASM Cluster File System (Oracle ACFS), and Oracle ASM Dynamic Volume Manager (Oracle ADVM) concepts and features in the following chapters: ## Introducing Oracle Automatic Storage Management This chapter presents Oracle ASM as an integrated volume manager and file system for single-instance databases and Oracle RAC, using disk groups to distribute, mirror, and manage database files with minimal downtime. It explains Oracle ASM and Flex ASM instances, disk groups, disks, allocation units, files, extents, striping, templates, failure groups, and redundancy options, and describes storage administration activities including disk discovery, mounting, adding and dropping disks, and online rebalancing. It also introduces Oracle ACFS and ADVM as extensions for managing general-purpose files and volumes. Read More: [Introducing Oracle Automatic Storage Management](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-i-introduction/introducing-oracle-automatic-storage-management.html) ## Exploring Considerations for Oracle ASM Storage This chapter describes how to plan and prepare storage for Oracle ASM, covering supported resources such as partitions, LUNs, logical volumes, and NFS, along with device ownership, permissions, discovery configuration, and platform-specific preparation. It explains multipathing requirements, recommends separating disk groups by workload, using similarly sized and performing disks, selecting suitable redundancy and failure groups, minimizing contention, aligning RAID stripe sizes with allocation units, and using ASM Filter Driver or platform multipathing to preserve device paths and permissions across restarts. Read More: [Exploring Considerations for Oracle ASM Storage](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-i-introduction/exploring-considerations-for-oracle-asm-storage.html) # Part II Oracle ASM Instances and Disk Groups Part II discusses the administration of Oracle ASM instances and disk groups in the following chapters: ## Administering Oracle ASM Instances Oracle ASM administration resembles database administration and can be performed with SQL\*Plus, ASMCMD, ASMCA, and SRVCTL. This material covers release compatibility, initialization parameters and parameter-file management, automatic memory management, disk discovery, disk-group startup, rebalancing, preferred reads, process and memory sizing, Oracle Restart, instance startup and shutdown, restricted mode, SRVCTL administration, configuration, upgrades, patching, and Active Session History. It also explains authentication through SYSASM, SYSDBA, SYSOPER, operating-system groups, password files, shared password files, and privilege separation; migration of database files to ASM using RMAN; and ASM audit-trail management through Syslog, operating-system auditing, and unified auditing. ASM supports older database releases subject to compatibility constraints, while clustered environments provide rolling upgrades and patches; parameter and password files can be backed up, copied, moved, or stored in ASM disk groups with appropriate compatibility settings. Read More: [Administering Oracle ASM Instances](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/administering-oracle-asm-instances.html) ## Administering Oracle ASM Instances Oracle Database 23ai introduces the static ASM initialization parameters `ASM_UNIFIED_AUDIT_LEVEL`, which audits either all actions or only `CONNECT`, `SHUTDOWN`, and `STARTUP` by default, and `ASM_UNIFIED_AUDIT_DESTINATION`, which writes records to spillover files or the system log by default; both apply to ASM, ASM Proxy, and Remote ASM and require an instance restart after changes. System-log auditing uses `UNIFIED_AUDIT_SYSTEMLOG`, now modifiable in ASM instances, while ASM unified auditing mandatorily records `CONNECT` and `SHUTDOWN` and does not retain full audit copies in OS files when redirected to syslog. Audit files support configurable maximum sizes of 1 KB–2,000,000 KB, maximum ages of 1–497 days, and purge intervals of 1–999 hours. For database instances supporting ASM without automatic memory management, Oracle recommends increasing `PROCESSES` by 16, `LARGE_POOL_SIZE` by 600 KB, and sizing `SHARED_POOL_SIZE` according to the aggregate ASM-resident datafile, redo, and online tempfile capacity and disk-group redundancy: approximately 1 MB per 100 GB plus 2 MB for external redundancy, per 50 GB plus 4 MB for normal redundancy, or per 33 GB plus 6 MB for high redundancy; automatic memory management is strongly recommended. Read More: [Administering Oracle ASM Instances](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/administering-oracle-asm-instances.html) ## Administering Oracle ASM Disk Groups Oracle ASM disk group administration covers creating, altering, mounting, dismounting, monitoring, and maintaining disk groups while database instances remain operational. Administrators manage attributes such as redundancy, compatibility, sector size, access control, repair intervals, content checking, preferred reads, thin provisioning, and storage type; create groups with defined disks, failure groups, quorum configuration, allocation units, and compatibility levels; and store database, recovery, OCR, and voting files appropriately. Disk groups can be modified online by adding, replacing, renaming, resizing, dropping, or undropping disks, managing ADVM volumes, and controlling automatic or manual rebalancing with power, wait, and phase options. Oracle ASM also provides disk discovery, capacity management, scrubbing for corruption detection and repair, sector-size validation, and monitoring through dynamic performance views and ASMCMD, with special considerations for Exadata, extended clusters, Flex disk groups, and compatibility requirements. Read More: [Administering Oracle ASM Disk Groups](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/administering-oracle-asm-disk-groups.html) ## Administering Oracle ASM Disk Groups Oracle ASM disk discovery uses paths defined by `ASM_DISKSTRING` and occurs during instance startup, disk-group mount, disk operations, relevant queries, ASMCA actions, and ASMCMD commands; discovered disks are classified as `MEMBER`, `CANDIDATE`, `PROVISIONED`, `FORMER`, or `FOREIGN`, with discovery limited to 10,000 disks and subject to partition, duplicate-path, and duplicate-header rules. Restricting `ASM_DISKSTRING` can improve discovery and mount performance, but multipathing, ASM Filter Driver, and ASMLIB conventions must be respected. Disk groups require sufficient free capacity to restore mirroring after failure; `REQUIRED_MIRROR_FREE_MB`, `USABLE_FILE_MB`, `TOTAL_MB`, and `FREE_MB` provide capacity guidance, with negative usable space indicating increased risk. Redundancy options include external, normal, high, flex, and extended, while failure groups isolate hardware risks and determine mirror placement, failure tolerance, and recovery behavior. ASM handles read and write I/O errors through mirror recovery, disk offlining, remapping, and possible dismounts; fast mirror resync tracks changes during transient outages, controlled by `DISK_REPAIR_TIME`, and preferred read failure groups can improve locality in extended clusters. Disk groups should contain similarly sized and performing disks, generally separate database files from recovery storage, and observe limits on disk groups, disks, files, capacity, and file sizes. Compatibility attributes—`COMPATIBLE.ASM`, `COMPATIBLE.RDBMS`, and `COMPATIBLE.ADVM`—enable release-specific features, must be advanced in the proper order, and cannot be reduced without creating a new disk group and moving files. ASM File Access Control restricts file access by database user, group, ownership, and permissions through disk-group attributes and `ALTER DISKGROUP` operations. Maintenance includes mounting, dismounting, restricted operation, consistency checks, dropping, renaming, and force-mounting groups with missing disks; force mounts leave unavailable disks offline until repaired or removed after the repair interval. Read More: [Administering Oracle ASM Disk Groups](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/administering-oracle-asm-disk-groups.html) ## Administering Oracle ASM Disk Groups Oracle ASM disk groups can be force-mounted with reduced redundancy when disks are temporarily unavailable, provided at least one extent copy for every file remains accessible; inaccessible disks are taken offline and may be dropped after `DISK_REPAIR_TIME` expires. Administrators can validate metadata consistency with `ALTER DISKGROUP ... CHECK`, optionally repair detected issues, and can drop disk groups—with `INCLUDING CONTENTS` or, cautiously, `FORCE` for unmountable groups—when files are no longer needed or redundancy must be changed. Cloned disk groups can be renamed using the two-phase `renamedg` utility, although Clusterware resources and database references require separate updates. Flex disk groups provide database- and file-group-level storage management, configurable redundancy, quotas, rebalancing, access control, and point-in-time PDB cloning; extended disk groups build on these capabilities for stretch clusters by distributing redundancy across data sites and a quorum site. File groups organize files by database, PDB, volume, or cluster and support properties such as redundancy, striping, priority, power limits, quotas, ownership, and user groups, while quota groups enforce physical-space limits across file groups within a disk group. Point-in-time cloning uses prepared mirror copies, file-group splitting, status monitoring, optional cleanup, and rebalance recovery after failures. Normal or high redundancy groups can be migrated to flex redundancy after meeting compatibility, failure-group, capacity, and template requirements, followed by conversion, rebalance, and verification of file redundancy. Read More: [Administering Oracle ASM Disk Groups](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/administering-oracle-asm-disk-groups.html) ## Administering Oracle ASM Files, Directories, and Templates Oracle ASM administration covers supported database file types, system-generated and alias file names, file creation and referencing methods, default disk-group locations, online data-file movement, file mapping, aliases, directories, XML DB access through `/sys/asm`, DBMS\_FILE\_TRANSFER operations, and templates. ASM supports most database files but not certain administrative files such as trace files and alert logs; fully qualified names identify existing files, while incomplete names and templates support managed creation. Aliases and user directories provide friendly references but are not Oracle Managed Files and may require manual cleanup. Templates define striping and redundancy, with system defaults based on file type and disk-group redundancy, and can be added, modified, or removed for customized file attributes. Read More: [Administering Oracle ASM Files, Directories, and Templates](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/administering-oracle-asm-files-directories-and-templates.html) ## Using Views to Display Oracle ASM Information Oracle ASM dynamic performance views provide operational, configuration, storage, file, client, template, and access-control information. Key views include `V$ASM_DISKGROUP` and `V$ASM_DISK` for disk-group and disk details, their lower-overhead `STAT` counterparts for monitoring, `V$ASM_FILE`, `V$ASM_ALIAS`, `V$ASM_TEMPLATE`, `V$ASM_ATTRIBUTE`, `V$ASM_CLIENT`, and `V$ASM_OPERATION` for files, aliases, templates, attributes, clients, and active operations. Disk-group numbers are mount-specific rather than persistent. File Access Control details are exposed through `V$ASM_USER`, `V$ASM_USERGROUP`, `V$ASM_USERGROUP_MEMBER`, and `V$ASM_FILE`, enabling administrators to inspect users, groups, memberships, permissions, and file ownership. Read More: [Using Views to Display Oracle ASM Information](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/using-views-to-display-oracle-asm-information.html) ## Administering Oracle ASM with Oracle Enterprise Manager Oracle Enterprise Manager Cloud Control provides a centralized interface for administering Oracle ASM, including accessing ASM status and capacity information, configuring initialization parameters, managing users, disk groups, disks, templates, files, aliases, access controls, and ASM Filter Driver provisioning. It supports disk group creation and maintenance, disk online/offline operations, rebalance control, compatibility and repair settings, scrubbing, performance monitoring, integrity checks, bad-block recovery, ASM file migration, alert and incident analysis through Support Workbench, and Oracle Flex ASM monitoring. Read More: [Administering Oracle ASM with Oracle Enterprise Manager](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/administering-oracle-asm-with-oracle-enterprise-manager.html) ## Performing Oracle ASM Data Migration with RMAN RMAN supports migrating databases, recovery areas, and individual data files between Oracle ASM and alternative storage. Migration generally involves preparing the database, creating backups or copies, configuring Oracle Managed Files and ASM destinations, restoring and switching files, recovering the database, recreating temporary and redo files, and optionally moving recovery-area contents. The procedures also cover reversing migration from ASM, handling standby and primary databases, disabling or restoring features such as Flashback Database and block change tracking when required, and relocating active data files between ASM disk groups using RMAN backup copies, switching, recovery, and cleanup. Read More: [Performing Oracle ASM Data Migration with RMAN](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/performing-oracle-asm-data-migration-with-rman.html) ## Managing Oracle ASM With ASMCA Oracle ASM Configuration Assistant (ASMCA) provides GUI and silent command-line tools for installing, configuring, and managing Oracle ASM instances, disk groups, ASM Filter Driver labels, file groups, quota groups, Oracle ADVM volumes, and Oracle ACFS file systems. The GUI starts with the asmca command from the Grid Infrastructure home, connects to the +ASM instance, and can start it when necessary. ASMCA supports creating instances with SYS and ASMSNMP credentials, registering listeners, adjusting initialization parameters, and managing disk groups by adding or dropping disks, configuring redundancy, failure and quorum groups, compatibility and allocation-unit settings, attributes, templates, labels, mounting state, and deletion. Its command-line mode uses asmca -silent with commands for configuring or deleting instances, setting parameters, creating disk groups, adding disks, editing attributes, managing Filter Driver labels, and creating or removing file and quota groups; options specify discovery paths, disks, failure groups, redundancy, passwords, compatibility, and related settings. Availability of some features depends on the deployment environment, such as Oracle RAC. Read More: [Managing Oracle ASM With ASMCA](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/managing-oracle-asm-with-asmca.html) ## Managing Oracle ASM with ASMCMD ASMCMD is Oracle ASM’s command-line utility for administering ASM instances, disk groups, files, directories, aliases, templates, volumes, access control, member clusters, ASM Filter Driver, audit trails, and related configuration. It supports interactive shell usage and noninteractive execution for scripts, with SYSASM as the default privilege and SYSDBA available for limited database operations. Users must configure the appropriate Oracle home, SID, authentication, and mounted disk groups, while understanding ASM fully qualified paths, relative and absolute paths, aliases, directory navigation, and wildcard behavior. Core instance commands manage discovery strings, clients, operations, password files, cluster state, patches, shutdown and startup, and SPFILE backup, copying, movement, and registration. Member-cluster commands create, modify, list, and remove cluster configurations and manifests. ASM Filter Driver commands configure filtering, manage disk discovery and labels, control data integrity, scan and refresh disks, and report driver state. Audit-management commands clean OS and unified audit files, configure retention properties and timestamps, create and manage purge jobs, and display audit configuration. ASMCMD also provides command-specific help, verbosity and diagnostic logging, version display, current-directory prompts, and documented return codes for automation. veloped identifiers that require quoting should be avoided because they may not work consistently across ASM management tools. Read More: [Managing Oracle ASM with ASMCMD](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/managing-oracle-asm-with-asmcmd.html) ## Managing Oracle ASM with ASMCMD This page documents ASMCMD audit, file-management, and disk-group-management commands. Audit operations create, drop, configure, monitor, enable, disable, and schedule purge jobs for OS or Unified audit trails, including file size, age, and archive timestamp settings. File commands support extraction, navigation, copying, space analysis, searching, listing, open-file inspection, block mapping, alias and directory management, and deletion while documenting wildcard, alias, redundancy, and remote-copy behavior. Disk-group commands provide capabilities to create, modify, check, repair, mount, dismount, drop, rebalance, monitor, and inspect disk groups, disks, attributes, open devices, and I/O statistics. XML-driven commands configure or alter disk groups, while metadata backup and restore commands preserve and recover ASM and selected ACFS configuration metadata; additional commands manage disk and failure-group availability, disk labels, sparse-file parents, and disk remapping. Read More: [Managing Oracle ASM with ASMCMD](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/managing-oracle-asm-with-asmcmd.html) ## Managing Oracle ASM with ASMCMD This page summarizes ASMCMD commands for administering Oracle ASM disk groups, file groups, quota groups, templates, file access control, and ASM Filter Driver. Disk operations include offlining and onlining disks or failure groups, controlling rebalance power and phases, remapping damaged block ranges, setting sparse-file parents, changing disk-group attributes, stamping and displaying disk labels, and dismounting disk groups. File-group and quota-group commands create, modify, list, move, and remove groups or files, with XML-based configuration supported for file groups. Template commands create, modify, list, and delete templates with configurable striping and redundancy. File access control commands manage ownership, groups, permissions, users, and passwords, subject to SYSASM, ownership, and operating-system identity requirements. ASM Filter Driver commands configure or deconfigure AFD, manage data integrity and filtering, set discovery strings, label or unlabel disks, scan and refresh devices, list labeled disks, and report driver state, with several operations requiring root privileges or stopped clusterware. Read More: [Managing Oracle ASM with ASMCMD](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-ii-oracle-asm-instances-and-disk-groups/managing-oracle-asm-with-asmcmd.html) # Part III Oracle Automatic Storage Management Cluster File System Part III discusses Oracle Automatic Storage Management Cluster File System (Oracle ACFS) and Oracle ASM Dynamic Volume Manager (Oracle ADVM), in the following chapters: ## Introducing Oracle ACFS and Oracle ADVM Oracle ACFS is a scalable, POSIX-compliant, general-purpose clustered file system integrated with Oracle ASM, Oracle ADVM, and Oracle Clusterware for managing database and application files across standalone and clustered environments. It provides dynamic resizing, ASM-based striping, mirroring, load distribution, snapshots, sparse files, high availability, shared namespaces, native API and operating-system access, NAS protocols, and support for large files and directories. Oracle ADVM presents ASM-backed dynamic volumes through standard operating-system block-device interfaces, enabling ACFS and other applications to use ASM storage. ACFS concepts include hierarchical namespaces, clusterwide or node-local mounts, driver-based operation, persistent mount registry management, database-file and database-home support, ASM integration, online backup through snapshots, and optional remote service for member clusters. Administration uses ASMCA, SRVCTL, ASMCMD, SQL\*Plus, and ACFS command-line tools, with Clusterware resources controlling drivers, volumes, mounts, dependencies, monitoring, and recovery. Compatibility attributes determine availability of capabilities such as snapshots, encryption, replication, compression, automatic resizing, sparse files, accelerator volumes, 4K sectors, snapshot duplication, and database storage. Security and encryption provide layered access controls and data-at-rest protection, although several features—including ACFS on Windows, Vault security, auditing, member-cluster remote service, and some encryption platforms—are deprecated or desupported in applicable releases. Proper privileges, resource dependencies, performance settings, controlled shutdown procedures, and platform-specific restrictions are required for reliable operation. Read More: [Introducing Oracle ACFS and Oracle ADVM](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/introducing-oracle-acfs-and-oracle-advm.html) ## Introducing Oracle ACFS and Oracle ADVM Oracle ACFS provides enterprise file-system capabilities including asynchronous compression for general-purpose files, auditing, snapshot-based replication, tagging, security, encryption, plugins, and accelerated metadata storage; feature availability depends on platform, release, and ASM/ADVM compatibility settings. Auditing records file access, privilege use, and command results in per-file-system trails with separated manager and auditor responsibilities, although ACFS Security and Auditing are deprecated from 19c. Replication asynchronously transfers snapshot contents and changes from a primary to one standby, supports tagging, role reversal, failover, SSH authentication, and integration with auditing, encryption, and security, but requires careful capacity, identity, compatibility, and wallet configuration. Accelerator volumes improve metadata performance when placed on faster storage, while ACFS NAS/MAX supplies highly available NFS and SMB services through Oracle Clusterware and virtual IPs, with platform and locking restrictions. ACFS remote service provides iSCSI-based storage access for supported member clusters from a Domain Services Cluster, requiring isolated transports, repositories, exports, appropriate performance capacity, and dedicated Clusterware resources; this feature and member clusters are deprecated. Oracle ADVM supplies dynamically managed virtual block devices backed by ASM volumes, enabling ACFS and other non-database file systems and applications, with volumes created and resized on demand when ASM and ADVM compatibility is at least 11.2. Read More: [Introducing Oracle ACFS and Oracle ADVM](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/introducing-oracle-acfs-and-oracle-advm.html) ## Using Views to Display Oracle ACFS Information Oracle ACFS and Oracle ADVM dynamic performance views provide information about file systems, volumes, encryption, security administrators, rules, rulesets, realms, snapshots, tags, replication, availability, capacity, and volume statistics. These views are accessible from the Oracle ASM instance, or from an ASM proxy instance in Flex ASM configurations, with Windows space values treated as approximate. Oracle ACFS also supports selected Oracle Database file-mapping views—V$MAP\_FILE, V$MAP\_FILE\_EXTENT, V$MAP\_ELEMENT, and V$MAP\_FILE\_IO\_STACK—after FILE\_MAPPING is enabled and DBMS\_STORAGE\_MAP.MAP\_ALL is executed; mapping is unavailable on Windows and V$MAP\_SUBELEMENT is unsupported. Read More: [Using Views to Display Oracle ACFS Information](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/using-views-to-display-oracle-acfs-information.html) ## Administering Oracle ACFS with Oracle Enterprise Manager Oracle Enterprise Manager Cloud Control provides GUI-based administration and monitoring for Oracle ACFS file systems, Oracle ADVM volumes, snapshots, security, encryption, and tagging, using the Oracle ASM home page and an ASM proxy instance when Flex ASM is configured. Administrators can create, mount, dismount, resize, delete, register, and inspect volumes and file systems; create and manage read-only, read-write, and child snapshots; initialize and configure security and encryption; manage administrators, rules, rulesets, and realms; and add, remove, or search file tags. Operations requiring host-level changes may generate commands and require root, administrator, or other appropriate credentials. Read More: [Administering Oracle ACFS with Oracle Enterprise Manager](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/administering-oracle-acfs-with-oracle-enterprise-manager.html) ## Managing Oracle ACFS and Oracle ADVM With ASMCA Oracle ASM Configuration Assistant supports GUI and command-line management of Oracle ADVM volumes and Oracle ACFS file systems, including creation, enabling, disabling, resizing, deletion, mounting, snapshots, security, encryption, and database-oriented file systems. Disk groups require appropriate ASM and ADVM compatibility attributes, and database file systems should use ASMCMD or SQL volume creation to preserve column striping of one. ASMCA can generate privileged operating-system commands, supports Windows administrator requirements, and provides silent commands for creating or deleting snapshots, creating volumes, and creating ACFS file systems; the command-line file-system creation operation does not mount the resulting file system. Read More: [Managing Oracle ACFS and Oracle ADVM With ASMCA](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/managing-oracle-acfs-and-oracle-advm-with-asmca.html) ## Managing Oracle ADVM with ASMCMD ASMCMD provides Oracle ADVM volume-management commands for creating, deleting, enabling, disabling, inspecting, resizing, configuring, and monitoring volumes in mounted ASM disk groups. The local ASM instance must be running, and required disk groups must be mounted. Key commands include `volcreate`, which defines volume size, striping, redundancy, and placement; `voldelete`, which removes volumes after associated file systems are stopped; `voldisable` and `volenable`, which control device availability; `volinfo`, which displays volume metadata and device details; `volresize`, which changes volume size but requires `acfsutil size` for ACFS volumes; `volset`, which manages usage and mount-path metadata; and `volstat`, which reports I/O counters and errors. Volumes are enabled automatically upon creation, have platform-specific naming and length restrictions, and should generally use disk-group redundancy; unprotected volumes are not recommended for production because storage failures can cause data loss. Active file systems must be dismounted before disabling, deleting, or certain resizing operations. Read More: [Managing Oracle ADVM with ASMCMD](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/managing-oracle-advm-with-asmcmd.html) ## Managing Oracle ACFS with Command-Line Tools Oracle ACFS and ADVM are managed through ASMCMD, SRVCTL, SQL\*Plus, ASMCA, operating-system commands, and acfsutil, with platform-specific support for Linux, Solaris, AIX, and Windows. Core workflows include creating ADVM volumes and ACFS file systems, registering, mounting, validating, accessing them across cluster nodes, and safely dismounting or removing them. The documentation also covers acfsutil privileges, help, version and trace-file management; snapshots; security realms, rules, administrators, auditing, and metadata backups; encryption and key management; extended-attribute tagging; snapshot-based replication with SSH, standby configuration, monitoring, pausing, resuming, failover, and capacity planning; and compression, cluster-domain operations, and command utilities. Linux guidance includes ACFS-specific mount options and offline or online fsck, while AIX guidance details mkfs, mount, and umount syntax, compatibility requirements, metadata block sizes, security options, and operational constraints. Disk-group compatibility, appropriate administrative privileges, consistent cluster mount points, and careful handling of encryption keys, snapshots, replication storage, and repair operations are essential throughout. Read More: [Managing Oracle ACFS with Command-Line Tools](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/managing-oracle-acfs-with-command-line-tools.html) ## Managing Oracle ACFS with Command-Line Tools Oracle ACFS file systems can be dismounted with the Solaris `umount` command by specifying either the Oracle ADVM volume device, such as `/dev/asm/volume1-123`, or the mounted file-system path, such as `/acfsmounts/acfs1`. Read More: [Managing Oracle ACFS with Command-Line Tools](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/managing-oracle-acfs-with-command-line-tools.html) ## Oracle ACFS Command-Line Tools for the Solaris Environment This topic summarizes Solaris-specific Oracle ACFS commands: `fsck` checks and repairs file systems, `mkfs` creates them, `mount` attaches them, and `umount` or `umountall` detaches them. Solaris extends these commands with ACFS options; forcibly dismounted disk groups may leave ADVM device files until the disk group is remounted. Read More: [Oracle ACFS Command-Line Tools for the Solaris Environment](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Oracle ACFS Command-Line Tools for the Solaris Environment) ## fsck On Solaris, `fsck -F acfs` checks a dismounted Oracle ACFS file system and requires root privileges and a loaded ACFS driver. It reports errors by default, while `-o a` repairs them; `-n` or `-y` suppresses prompts, and verbose, force, and help options are available. Temporary working files may be created during checking, and unrecoverable objects are placed in `/lost+found` with identifier-based names. Read More: [fsck](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/fsck) ## mkfs Solaris `mkfs -F acfs` creates an Oracle ACFS file system on an ADVM volume without requiring root privileges, provided the user owns the device. Options support forced formatting, naming, verbose output, metadata block sizes of 512 or 4096 bytes, sizing, and release compatibility. Minimum sizes are 200 MB for 512-byte metadata and 512 MB for 4 KB metadata; compatibility and sector-size requirements govern 4 KB formatting. Read More: [mkfs](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/mkfs) ## mount Solaris `mount -F acfs` attaches a formatted Oracle ACFS volume to an existing directory, requires root privileges, and supports read-only/read-write, device, execution, set-ID, verbose, and automatic mounting of registered file systems. A file system should use one consistent mount point across cluster members, and the `all` option mounts registered file systems whose automatic-start setting is enabled. Read More: [mount](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/mount) ## umount/umountall Solaris `umount` detaches an Oracle ACFS file system specified by its mount point or ADVM volume device, while `umountall -F acfs` detaches all ACFS file systems on the current node. Both commands require root privileges, wait for completion, and fail if a file system is busy; `-V` can validate an `umount` command line without executing it. Read More: [umount/umountall](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/umount/umountall) ## fsck On AIX, `fsck -V acfs` checks and repairs a dismounted Oracle ACFS file system using an ADVM volume device. Root privileges and a loaded ACFS driver are required; checking is the default, while `-o a` repairs errors, `-n` and `-y` answer prompts automatically, and force and verbose modes are available. Temporary files support the operation, and unrecoverable objects may be placed in `/lost+found`. Read More: [fsck](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/fsck) ## umount/umountall AIX `umount` detaches an Oracle ACFS file system by mount point or ADVM volume device, and `umountall -F acfs` detaches all ACFS file systems on the current node. The commands require root privileges, wait until dismounting completes, and fail when the target file system is busy. Read More: [umount/umountall](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/umount/umountall) ## Oracle ACFS Command-Line Tools for the AIX Environment This topic summarizes AIX Oracle ACFS commands and explains the `oracle_devmgmt` security role, which authorizes ACFS and ADVM device configuration, removal, and definition. The role is assigned to the Grid Infrastructure and ASM administrators; users may need to activate it with `swrole` or open a new shell. AIX force-dismounted disk groups can leave ADVM device files until remounting. Read More: [Oracle ACFS Command-Line Tools for the AIX Environment](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Oracle ACFS Command-Line Tools for the AIX Environment) ## fsck On AIX, `fsck -V acfs` checks and repairs a dismounted Oracle ACFS file system using an ADVM volume device. Root privileges and a loaded ACFS driver are required; checking is the default, while `-o a` repairs errors, `-n` and `-y` answer prompts automatically, and force and verbose modes are available. Temporary files support the operation, and unrecoverable objects may be placed in `/lost+found`. Read More: [fsck](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/fsck) ## mkfs AIX `mkfs -V acfs` creates the on-disk structure for an Oracle ACFS file system on an ADVM device without inherently requiring root privileges. It supports naming, sizing, forced formatting, verbose output, 512- or 4096-byte metadata blocks, and release compatibility. The minimum sizes, compatibility rules, driver requirement, and 4 KB sector behavior parallel Solaris ACFS formatting. Read More: [mkfs](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/mkfs) ## mount AIX `mount -v acfs` attaches a formatted Oracle ACFS volume to an existing directory and requires root privileges. It supports read-only/read-write, security-related, device, verbose, and automatic mounting options; the `all` option mounts registered file systems configured for automatic startup. Mount points should be unique per file system and consistent across cluster members. Read More: [mount](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/mount) ## umount/umountall AIX `umount` detaches an Oracle ACFS file system using its mount point or ADVM volume device, while `umountall -F acfs` detaches all ACFS file systems on the current node. Root privileges are required, commands wait for complete dismounting, and busy file systems cause failure. Read More: [umount/umountall](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/umount/umountall) ## Oracle ACFS Command-Line Tools for the AIX Environment This topic summarizes AIX Oracle ACFS commands and explains the `oracle_devmgmt` security role, which authorizes ACFS and ADVM device configuration, removal, and definition. The role is assigned to the Grid Infrastructure and ASM administrators; users may need to activate it with `swrole` or open a new shell. AIX force-dismounted disk groups can leave ADVM device files until remounting. Read More: [Oracle ACFS Command-Line Tools for the AIX Environment](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Oracle ACFS Command-Line Tools for the AIX Environment) ## fsck On AIX, `fsck -V acfs` checks and repairs a dismounted Oracle ACFS file system using an ADVM volume device. Root privileges and a loaded ACFS driver are required; checking is the default, while `-o a` repairs errors, `-n` and `-y` answer prompts automatically, and force and verbose modes are available. Temporary files support the operation, and unrecoverable objects may be placed in `/lost+found`. Read More: [fsck](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/fsck) ## mkfs AIX `mkfs -V acfs` creates the on-disk structure for an Oracle ACFS file system on an ADVM device without inherently requiring root privileges. It supports naming, sizing, forced formatting, verbose output, 512- or 4096-byte metadata blocks, and release compatibility. The minimum sizes, compatibility rules, driver requirement, and 4 KB sector behavior parallel Solaris ACFS formatting. Read More: [mkfs](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/mkfs) ## mount AIX `mount -v acfs` attaches a formatted Oracle ACFS volume to an existing directory and requires root privileges. It supports read-only/read-write, security-related, device, verbose, and automatic mounting options; the `all` option mounts registered file systems configured for automatic startup. Mount points should be unique per file system and consistent across cluster members. Read More: [mount](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/mount) ## umount/umountall AIX `umount` detaches an Oracle ACFS file system using its mount point or ADVM volume device, while `umountall -F acfs` detaches all ACFS file systems on the current node. Root privileges are required, commands wait for complete dismounting, and busy file systems cause failure. Read More: [umount/umountall](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/umount/umountall) ## Oracle ACFS Command-Line Tools for Windows Environments This topic lists Windows commands for checking, formatting, mounting, dismounting, and detaching Oracle ACFS, along with `advmutil` commands for non-ACFS file systems on ADVM volumes. Oracle ACFS on Windows is deprecated beginning with ACFS 19c 19.5 and may be removed in a future release; migration options include ASM, DBFS, or Windows shares. Read More: [Oracle ACFS Command-Line Tools for Windows Environments](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Oracle ACFS Command-Line Tools for Windows Environments) ## acfschkdsk Windows `acfschkdsk` checks and repairs an Oracle ACFS file system that has been dismounted clusterwide. It requires the ACFS driver and normally ensures exclusive access; `/a` repairs errors, `/n` or `/y` handles prompts, `/f` forces mountable state, and `/v` enables progress reporting. Working files are temporary, and unrecoverable objects are placed in `\lost+found`, accessible only to Administrators. Read More: [acfschkdsk](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfschkdsk) ## acfsdismount Windows `acfsdismount` removes the namespace attachment and dismounts an Oracle ACFS file system by drive letter, full mount path, or `/all` for every file system on the node. Administrator privileges are required, verbose output is available, and open references from applications such as scanners or management tools can prevent dismounting. Read More: [acfsdismount](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsdismount) ## acfsformat Windows `acfsformat` quickly creates the on-disk structure required for an Oracle ACFS file system and requires Administrator privileges and a loaded ACFS driver. It supports verbose output, forced formatting, file-system labels, 512- or 4096-byte metadata blocks, selected device capacity, and release compatibility, subject to minimum-size, sector, and compatibility constraints. Read More: [acfsformat](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsformat) ## acfsmountvol Windows `acfsmountvol` mounts a formatted Oracle ACFS volume to a drive letter or empty directory, can mount all registry-defined file systems, and lists mounted file systems when invoked without arguments. Administrator privileges are required; mount points may be nested but each file system should use only one consistent mount point across cluster members. Read More: [acfsmountvol](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsmountvol) ## acfsutil detach Windows `acfsutil detach` unregisters Oracle ACFS as a base file system and removes driver device objects so the ACFS driver can be unloaded after all volumes are dismounted. Only the Windows Administrator can run it, and Oracle shutdown scripts invoke it automatically. Read More: [acfsutil detach](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil detach) ## advmutil dismount Windows `advmutil dismount` removes access to non-ACFS file systems on Oracle ADVM volumes by drive letter, directory, all registered volumes, or a specified disk group. The optional `/unregister` removes the device and drive-letter registration from the system registry. ASM must be running with the required disk groups mounted and volumes enabled. Read More: [advmutil dismount](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil dismount) ## advmutil list Windows `advmutil list /registry` displays registered non-ACFS ADVM volume devices and their associated drive letters from the system registry. The local ASM instance must be running, required disk groups must be mounted, and volumes must be enabled. Read More: [advmutil list](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil list) ## advmutil mount Windows `advmutil mount` exposes non-ACFS ADVM volumes through a drive letter or directory, optionally registering the mapping for automatic recreation, or mounts all registered volumes. ASM, mounted disk groups, and enabled volumes are prerequisites; drive-letter mounting is required before formatting an ADVM volume with NTFS. Read More: [advmutil mount](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil mount) ## Oracle ACFS Command-Line Tools for Tagging Oracle ACFS tagging commands display, add, and remove tags on files and directories. Tags can be applied recursively, but Solaris symbolic-link tags are not preserved by backup, restore, copy, move, tar, or pax operations. Tagging behavior is subject to file permissions and security-realm browse permissions. Read More: [Oracle ACFS Command-Line Tools for Tagging](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Oracle ACFS Command-Line Tools for Tagging) ## acfsutil tag info `acfsutil tag info` displays paths of tagged Oracle ACFS files and directories, optionally recursively, filtered by an exact or case-insensitive partial tag name. With no paths, it searches all ACFS mount points. Users need read access, and security-realm restrictions can suppress results without appropriate browse permissions. Read More: [acfsutil tag info](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil tag info) ## acfsutil tag set `acfsutil tag set` assigns a tag to one or more files or directories, optionally recursively and with progress output. Tags support limited ASCII characters and names up to 32 characters; `all` is reserved. Existing tags remain, new files inherit parent-directory tags, and users need permission to modify the targets. Read More: [acfsutil tag set](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil tag set) ## acfsutil tag unset `acfsutil tag unset` removes a specified tag or all tags from files and directories, optionally recursively with progress reporting. Other tags remain when one tag is removed, and the command requires permission to modify targets plus appropriate browse access within protected security realms. Read More: [acfsutil tag unset](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil tag unset) ## Oracle ACFS Command-Line Tools for Replication This topic summarizes snapshot-based Oracle ACFS replication commands for controlling background processing, initializing and synchronizing replication, comparing data, pausing or resuming activity, performing failover or role changes, terminating replication, tracing operations, updating metadata, and upgrading existing replication installations. Read More: [Oracle ACFS Command-Line Tools for Replication](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Oracle ACFS Command-Line Tools for Replication) ## acfsutil repl bg `acfsutil repl bg` starts, stops, or reports on the replication background process for a replicated mount point or snapshot. Replication requires this clusterwide process on the primary cluster; initialization starts and registers it with Clusterware so it can restart automatically after reboot or failure. Read More: [acfsutil repl bg](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil repl bg) ## Managing Oracle ACFS with Command-Line Tools Oracle ACFS command-line tools support comprehensive snapshot-based replication management, including monitoring background processes, comparing primary and standby contents, initializing and updating replication, pausing and resuming operations, synchronizing data, performing planned switchovers or failovers, reversing roles, terminating replication, tracing activity, and upgrading legacy replication. The commands also provide auditing functions to initialize, enable, disable, inspect, archive, read, and purge audit trails, although ACFS auditing and security are deprecated from Oracle ACFS 19c Release 19.5. Security commands manage administrators, passwords, batch operations, file-system and realm security, and security metadata. Operational considerations include correct primary/standby sequencing, SSH configuration, replication-user privileges, quiescing applications before role changes or final synchronization, appropriate handling of unmounts and failovers, and restricting administrative commands to authorized roles. Read More: [Managing Oracle ACFS with Command-Line Tools](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/managing-oracle-acfs-with-command-line-tools.html) ## Managing Oracle ACFS with Command-Line Tools This page summarizes Oracle ACFS command-line administration for security, encryption, keystores, and snapshots. Security commands initialize and prepare file systems, inspect realms and secured files, save or load metadata, create, clone, edit, audit, and destroy realms, rules, and rule sets, and add or remove users, groups, command filters, and protected paths; these operations generally require a security administrator. Encryption commands initialize key storage, inspect encryption status, enable or disable encryption, set algorithms and key lengths, rekey volumes or files, back out encryption, and migrate between SSO and PKCS keystores, with administrative privileges required for system-wide operations. Snapshot commands provide operations to convert snapshot modes and, as summarized, create, delete, duplicate, inspect, link, quota-manage, remaster, and rename snapshots. The documented options support recursive processing, AES encryption with 128-, 192-, or 256-bit keys, audit authorization and violation tracking, policy replication, and controlled access based on users, groups, applications, hosts, times, and file-system operations. Read More: [Managing Oracle ACFS with Command-Line Tools](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/managing-oracle-acfs-with-command-line-tools.html) ## Managing Oracle ACFS with Command-Line Tools Oracle ACFS command-line tools manage snapshots, compression, cluster-domain services, exports, transports, compatibility, defragmentation, and file-system operations. Snapshot commands support creation, deletion, duplication, inspection, linking, quotas, remastering, and renaming, with access and migration restrictions varying by operation; compression commands control file compression and reporting; cluster-domain utilities manage remote-service status, credentials, exports, sessions, and transports; general utilities handle acceleration volumes, compatibility, defragmentation, freezing, and related administration. Administrative or root privileges are commonly required. Read More: [Managing Oracle ACFS with Command-Line Tools](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/managing-oracle-acfs-with-command-line-tools.html) ## acfsutil snap delete Deletes a named snapshot from a mounted Oracle ACFS file system and removes its representation under `.ACFS/snaps`. Open files and directory references do not prevent deletion, but associated storage is reclaimed asynchronously after references close; pending cleanup is visible through snapshot information. The operation fails during rolling migration and requires administrator privileges or membership in the Oracle ASM administrator group. Read More: [acfsutil snap delete](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil snap delete) ## acfsutil snap duplicate apply Applies a snapshot duplication stream from standard input to the mounted file system or a specified writable target snapshot. Initial applies require an empty target, while incremental applies require contents matching the prior source snapshot; concurrent changes cause failure, and an identical stream returns status 2 without modifying the target. Optional backup snapshots preserve the last successful target state, while exit statuses 0, 1, and 2 indicate success, fatal failure, and duplicate-stream no-op respectively; root privileges are required. Read More: [acfsutil snap duplicate apply](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil snap duplicate apply) ## acfsutil snap duplicate create Creates a snapshot duplication stream on standard output for transfer to another compatible Oracle ACFS file system. Supplying only a new snapshot produces an initial stream containing the complete snapshot, while specifying an old snapshot produces an incremental stream containing differences; parent and restart options support common snapshot ancestry and interrupted transfers. The command normally feeds `acfsutil snap duplicate apply`, requires root privileges, and returns status 0 on success or 1 on fatal failure. Read More: [acfsutil snap duplicate create](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil snap duplicate create) ## acfsutil snap info Displays metadata for one or all snapshots, including name, type, parent, creation time, location, storage usage, quota data, replication or duplication status, and deletion progress. The `-t` option presents snapshot relationships as a tree, while pending deletion states identify snapshots awaiting open-file closure or background cleanup. Usage statistics include metadata and may be temporarily inaccurate because ACFS updates them asynchronously. Read More: [acfsutil snap info](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil snap info) ## acfsutil snap link Creates or deletes one specialized snapshot link that exposes a snapshot through an alternate path outside `.ACFS/snaps`. Links can be created only in the primary file system, require `COMPATIBLE.ADVM` 18.0 or later, and must be managed with `acfsutil snap link` rather than ordinary file-system commands; each snapshot supports only one link, which can be recreated at another location or name. Read More: [acfsutil snap link](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil snap link) ## acfsutil snap quota Sets, increases, or decreases the storage limit for a specified snapshot using byte or K/M/G/T/P units. The quota establishes an upper bound on storage added to the snapshot rather than reserving space, applies to eligible snapshots created with `COMPATIBLE.ADVM` 12.2 or later, and can be used for both read-only and read-write snapshots. Warnings occur near 90 percent utilization, while writes exceeding the limit fail with `EDQUOT` or possibly `ENOSPC`; root privileges are required. Read More: [acfsutil snap quota](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil snap quota) ## acfsutil snap remaster Replaces the base of an unmounted Oracle ACFS file system with the point-in-time state of an existing snapshot, reintegrating its extents and leaving no snapshots. The operation is irreversible, requires administrator privileges, and can resume an interrupted remaster with `-c`; it cannot run while replication, security, encryption, or plug-ins are enabled. Read More: [acfsutil snap remaster](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil snap remaster) ## acfsutil snap rename Safely renames an existing Oracle ACFS snapshot while preserving its contents and handling open references similarly to a parent-directory rename. The operation requires administrator privileges but is unsupported for snapshots associated with pluggable databases or replication, because renaming can create inconsistencies. Read More: [acfsutil snap rename](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil snap rename) ## Oracle ACFS Command-Line Tools for Compression Oracle ACFS compression commands provide a compact administrative interface for copying files with compression, inspecting compression usage, enabling compression, and disabling compression. Compression applies by default to files created after activation, while existing files retain their current state; Oracle ACFS compression is not supported for Oracle Database files. Read More: [Oracle ACFS Command-Line Tools for Compression](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Oracle ACFS Command-Line Tools for Compression) ## acfsutil compress copy Copies files into a target directory while optionally compressing them, selecting a compression unit, recursively copying directories, preserving uncompressed copies with `-n`, displaying verbose output, and overwriting existing targets with `-f`. Without `-f`, the operation stops when an existing target is encountered; copying to a compression-capable file system with compression disabled requires the `-n` option. Read More: [acfsutil compress copy](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil compress copy) ## acfsutil compress info Reports compression details for a specified file, including compression-unit size, disk space used, space saved, and compressed usage as a percentage of the uncompressed size. It is intended for assessing the effectiveness and storage impact of Oracle ACFS compression. Read More: [acfsutil compress info](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil compress info) ## acfsutil compress off Disables Oracle ACFS compression for a mounted file system. Files created afterward are uncompressed, while files already compressed remain compressed; root or system-administrator privileges are required. Read More: [acfsutil compress off](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil compress off) ## acfsutil compress on Enables Oracle ACFS compression for a mounted file system, optionally selecting the compression algorithm; `lzo` is currently the only and default algorithm. New files are compressed by default, existing uncompressed files remain unchanged, and root or system-administrator privileges are required. Compression should not be enabled for file systems intended to contain Oracle Database files. Read More: [acfsutil compress on](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil compress on) ## Oracle ACFS Command-Line Tools for Oracle ACFS in the Cluster Domain Cluster-domain utilities manage Oracle ACFS remote service prerequisites, credentials, cluster state, remote file attributes, exports, sessions, and network transports. The command set includes node support, installation, and loading checks; credential and cluster information management; remote-file protection; Domain Services Cluster export lifecycle operations; member-cluster session monitoring; and transport configuration. Read More: [Oracle ACFS Command-Line Tools for Oracle ACFS in the Cluster Domain](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Oracle ACFS Command-Line Tools for Oracle ACFS in the Cluster Domain) ## acfsremote installed Checks whether Oracle ACFS remote-service drivers and applicable system transports are installed on the current node. It supports member-cluster and Domain Services Cluster checks, optional tracing, and explicit cluster-role selection. Read More: [acfsremote installed](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsremote installed) ## acfsremote loaded Checks whether Oracle ACFS remote-service resources and transports are loaded and running. A transport that is unused or unconfigured may correctly report as not loaded even when the remote service itself is operational; the command applies to both member and Domain Services Clusters. Read More: [acfsremote loaded](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsremote loaded) ## acfsremote supported Determines whether the current node meets the kernel, package, and transport requirements for Oracle ACFS remote service. It supports member-cluster and Domain Services Cluster checks, optional tracing, and transport-specific capability reporting. Read More: [acfsremote supported](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsremote supported) ## acfsutil cluster credential Generates, lists, updates, removes, and imports Oracle ACFS remote-service credentials, including operating-system user and group permissions. It supports member-cluster registration and manifest exchange, applies across cluster types, and is generally used by setup procedures rather than directly by end users. Read More: [acfsutil cluster credential](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil cluster credential) ## acfsutil cluster info Displays cluster type and internal state used to verify synchronization between the Oracle ACFS kernel cluster and Oracle ASM. Output includes node membership, rebuild master, incarnation, cluster state, remote-service mode, storage mode, DLM status, and node addresses; the command applies to all cluster types. Read More: [acfsutil cluster info](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil cluster info) ## acfsutil remote clear Removes the Oracle ACFS remote attribute from a specified file, allowing a system administrator to remove or truncate the file on disk. Read More: [acfsutil remote clear](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil remote clear) ## acfsutil remote set Sets the Oracle ACFS remote attribute on a specified file, preventing a system administrator from removing or truncating the file on disk. Read More: [acfsutil remote set](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil remote set) ## advmutil export create Creates a Domain Services Cluster export, allocates a fully provisioned backing file, and associates it with a member cluster and ACFS storage repository. The export name becomes the member-cluster volume name; `-f` permits reuse of an existing backing file. Export snapshots are created on the Domain Services Cluster and can be exposed through snapshot links and reused export mappings. Read More: [advmutil export create](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil export create) ## advmutil export list Queries Domain Services Cluster exports and member-cluster information using configurable filters, grouping, output fields, active-only selection, and header suppression. It supports grouping by cluster name, cluster GUID, or storage repository and is suitable for both administration and scripting. Read More: [advmutil export list](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil export list) ## advmutil export lsof Lists active files associated with exports across repositories or within a specified repository path. The command can restrict output to active exports and applies only to the Domain Services Cluster, supporting investigation of export usage and activity. Read More: [advmutil export lsof](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil export lsof) ## advmutil export mapping Reexports all configured exports or those belonging to a specified member cluster. It is used to restore export accessibility after administrative actions remove access and applies only to the Domain Services Cluster. Read More: [advmutil export mapping](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil export mapping) ## advmutil export remove Removes export configuration metadata for a member cluster and repository mapping. The backing file remains by default and can later be reused with `-f`; `-b` removes it and releases repository space, while `-f` and `-y` control forced removal and confirmation behavior. Read More: [advmutil export remove](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil export remove) ## advmutil export resize Adds storage to an export’s backing file and correspondingly resizes the member-cluster device. The member cluster must resize its ACFS file system with `acfsutil size` to use the additional capacity unless automatic resize is configured; shrinking requires resizing the member file system first. The command applies only to the Domain Services Cluster. Read More: [advmutil export resize](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil export resize) ## advmutil session list Displays current Oracle ACFS remote-service transport sessions on a member cluster, optionally filtered by node or transport and expanded with verbose XML output. Session states include `ONLINE`, `REFRESH`, and `RESCAN`, making the command useful for operational diagnostics. Read More: [advmutil session list](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil session list) ## advmutil transport create Creates a Domain Services Cluster transport for a member cluster using a transport VIP, network number, or alternate resource identifier. Multiple transports can support multipathing and failover, VIPs may be shared, and each transport receives a cluster, type, and sequence-based identifier. Read More: [advmutil transport create](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil transport create) ## advmutil transport list Displays configured transports on the Domain Services Cluster, optionally filtered by member-cluster name, cluster GUID, or transport ID. Verbose mode provides full configuration details, while sequence numbers and transport IDs can be used for targeted member-cluster diagnostics. Read More: [advmutil transport list](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil transport list) ## advmutil transport remove Removes a specified transport from a member cluster on the Domain Services Cluster. If it is the last transport using an associated VIP resource, that resource is also removed. Read More: [advmutil transport remove](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil transport remove) ## Oracle ACFS Command-Line Utilities Oracle ACFS command-line utilities cover accelerator replacement, compatibility management, directory and file defragmentation, file-system freezing and thawing, information and storage reporting, plug-in control, mount registration, file-system removal, scrubbing, resizing, version reporting, and Oracle ADVM volume inspection. They provide the principal administrative interface for maintaining ACFS and related ADVM resources. Read More: [Oracle ACFS Command-Line Utilities](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Oracle ACFS Command-Line Utilities) ## acfsutil accel replace Replaces an existing accelerator volume with a new volume, which must be at least as large as the current accelerator. The file system must be unmounted on every node, and a larger replacement requires a subsequent resize operation after remounting; root or Oracle ASM administrator privileges are required. Read More: [acfsutil accel replace](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil accel replace) ## acfsutil compat get Displays the Oracle ACFS file-system compatibility level and the disk group’s `COMPATIBLE.ADVM` setting for a mounted file system. It identifies the effective feature compatibility established during file-system creation or by a prior compatibility change. Read More: [acfsutil compat get](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil compat get) ## acfsutil compat set Raises the compatibility level of an Oracle ACFS file system to a specified release version subject to `COMPATIBLE.ADVM` and the running Grid Infrastructure release. Compatibility cannot be downgraded, and increasing it may prevent mounting with older Grid Infrastructure releases. Read More: [acfsutil compat set](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil compat set) ## acfsutil defrag dir Defragments files in a specified directory, optionally traversing subdirectories with `-r`. The caller must have write access to affected files and administrator privileges or Oracle ASM administrator-group membership. Read More: [acfsutil defrag dir](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil defrag dir) ## acfsutil defrag file Defragments one or more specified files, with the optional `-i` mode estimating the possible reduction in extents without performing the operation. Write access is required for defragmentation, read access for estimation, and administrator privileges are required. Read More: [acfsutil defrag file](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil defrag file) ## acfsutil freeze Temporarily halts modification activity on a mounted Oracle ACFS file system, optionally flushing pending data first with `-f`. It supports point-in-time image creation without stopping applications; normal activity resumes with the corresponding thaw operation. Read More: [acfsutil freeze](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil freeze) ## Managing Oracle ACFS with Command-Line Tools Use Oracle ACFS command-line tools cautiously, especially `acfsutil freeze`, which can cause application timeouts, database instance termination after prolonged freezing, and replication interruptions. Frozen replicated file systems may block reverse, synchronization, or termination operations, so administrative actions should be brief and coordinated with database and replication activity. Read More: [Managing Oracle ACFS with Command-Line Tools](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iii-oracle-automatic-storage-management-cluster-file-system/managing-oracle-acfs-with-command-line-tools.html) ## acfsutil info file The `acfsutil info file` command displays detailed information about one or more Oracle ACFS files, including ownership, size, allocation, timestamps, tags, and extent mappings from ACFS to ASM devices. Options provide detailed extent data, metadata extents, usage and snapshot inheritance information, or extent counts only; read access to the file is required. Read More: [acfsutil info file](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil info file) ## acfsutil info fs The `acfsutil info fs` command reports Oracle ACFS file-system configuration, status, capacity, volumes, snapshots, replication, compression, encryption, security, fragmentation, and operational statistics. It supports querying individual properties, monitoring change rates at intervals, and displaying fragmentation details; states such as Available, Offline, and Corrupt indicate whether the file system is operational or requires repair. Read More: [acfsutil info fs](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil info fs) ## acfsutil info id The `acfsutil info id` command translates an internal Oracle ACFS file identifier into its corresponding path at a specified mount point. This is useful for investigating driver-reported I/O errors, and requires administrator privileges or membership in the Oracle ASM administrator group. Read More: [acfsutil info id](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil info id) ## acfsutil info storage The `acfsutil info storage` command provides platform-independent storage-consumption information across Oracle ASM disk groups, ADVM volumes, ACFS file systems, and snapshots. It supports selectable units, summary or detailed output, disk-group filtering, redundancy-aware free-space calculations, and requires root or `asmadmin` privileges. Read More: [acfsutil info storage](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil info storage) ## acfsutil plugin disable The `acfsutil plugin disable` command stops Oracle ACFS plug-in metric collection and communication with the associated plug-in application for a mounted file system. Administrator privileges or membership in the Oracle ASM administrator group is required. Read More: [acfsutil plugin disable](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil plugin disable) ## acfsutil plugin enable The `acfsutil plugin enable` command activates ACFS plug-in monitoring for selected tagged files or all files, using predefined metric types such as `acfsmetric1` and `acfsmetric2`. Metrics may be delivered through application polling or periodic posting, with configurable intervals up to 60 minutes; collection covers user file I/O but excludes internal ACFS operations and replication files. Read More: [acfsutil plugin enable](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil plugin enable) ## acfsutil plugin info The `acfsutil plugin info` command displays the plug-in state, metric type, enabled tags, delivery method, and posting interval for a mounted Oracle ACFS file system. Administrator privileges or membership in the Oracle ASM administrator group is required. Read More: [acfsutil plugin info](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil plugin info) ## acfsutil registry The `acfsutil registry` command manages persistent Oracle ACFS mount registrations used for automatic mounting at startup. Administrators can add, modify, delete, list, or query entries, specify mount options, eligible nodes, descriptions, and permitted users, while any user may display registry contents; registration changes require root or `asmadmin` privileges and are unsupported in Oracle Restart configurations. Read More: [acfsutil registry](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil registry) ## acfsutil rmfs The `acfsutil rmfs` command removes a dismounted Oracle ACFS file system by disabling its superblock, requiring root or `asmadmin` privileges. The operation clears associated volume mount and usage metadata, but the file system may be recoverable with repair tools and the device can later be reformatted. Read More: [acfsutil rmfs](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil rmfs) ## acfsutil scrub The `acfsutil scrub` command checks Oracle ACFS directory metadata, file metadata, and user data for mirror inconsistencies and reports affected paths, offsets, lengths, and volume locations. It supports metadata-only, recursive, quiet, extension-exclusion, snapshot-exclusion, error-limit, I/O-load, and trace-level controls, and requires root privileges on supported Linux and AIX systems. Read More: [acfsutil scrub](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil scrub) ## acfsutil size The `acfsutil size` command grows or shrinks an Oracle ACFS file system or configures automatic resizing through minimum-free-space increments and maximum-size limits. It can estimate data movement, resize a specific volume, and automatically respond to low or fragmented space, but operations may be time-consuming, partially succeed, alter fragmentation, or require compatible ADVM settings and sufficient ASM capacity. Read More: [acfsutil size](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil size) ## acfsutil thaw The `acfsutil thaw` command resumes file-system activity previously suspended with `acfsutil freeze`. It accepts the mounted file-system path and should be used promptly after maintenance to avoid blocked applications and related service disruption. Read More: [acfsutil thaw](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil thaw) ## acfsutil version The `acfsutil version` command displays the installed Oracle ACFS release, while `-v` provides verbose kernel and command build information, including full versions, hashes, and bug identifiers. Administrator privileges or membership in the Oracle ASM administrator group is required. Read More: [acfsutil version](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/acfsutil version) ## advmutil canonical The `advmutil canonical` command converts an Oracle ADVM volume-device identifier into its normalized canonical form. It is particularly useful in scripts and on Windows, where device names may include alternate prefixes that other utilities do not accept consistently. Read More: [advmutil canonical](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil canonical) ## advmutil volinfo The `advmutil volinfo` command displays Oracle ADVM volume properties such as device name, size, resize increment, redundancy, striping, disk group, volume name, and compatibility level. Default output is human-readable, while `-l` produces colon-separated fields and `-L` produces space-separated output suitable for scripting. Read More: [advmutil volinfo](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/advmutil volinfo) ## Deregistering, Dismounting, and Disabling Volumes and Oracle ACFS File Systems An ACFS file system can be deregistered to prevent automatic mounting, dismounted independently for maintenance or checking, and have its underlying volume disabled only after dismounting. These actions do not destroy file-system data, but deregistered or dismounted file systems must be explicitly mounted again, and disabled volumes must be re-enabled before access. Read More: [Deregistering, Dismounting, and Disabling Volumes and Oracle ACFS File Systems](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Deregistering, Dismounting, and Disabling Volumes and Oracle ACFS File Systems) ## Removing an Oracle ACFS File System and a Volume Permanent removal requires deregistering the file system, dismounting it from every cluster node, removing it with `acfsutil rmfs` when necessary, optionally disabling the volume, and deleting the volume with ASMCMD. This sequence destroys the file-system data and should be performed only after confirming that the volume and its contents are no longer required. Read More: [Removing an Oracle ACFS File System and a Volume](OSTMG 19c/Part III Oracle Automatic Storage Management Cluster File System/19c/Removing an Oracle ACFS File System and a Volume) # Part IV Advanced Topics Page This part introduces advanced Oracle storage and cluster administration topics, including Oracle ACFS concepts and snapshot-based replication, Oracle Flex ASM management, Oracle ASM Filter Driver administration, and creating database files in Oracle ASM with SQL\*Plus. Read More: [Part IV Advanced Topics Page](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iv-advanced-topics.html) ## Understanding Oracle ACFS Advanced Topics Oracle ACFS advanced administration covers storage and file-count limits, ADVM volume configuration, error recovery, NFS export requirements, loopback devices, driver and resource management, Oracle Restart limitations, diagnostic commands, plug-in and tagging APIs, and I/O failure troubleshooting. ACFS supports extensive mount, file, directory, and capacity limits governed partly by platform and ASM compatibility; failures require controlled dismount, synchronization, remount, or file-system checking procedures. The guidance explains cloning databases and PDBs efficiently with ACFS snapshots, including control-file, parameter, redo, tempfile, RAC, CRS, and service configuration, and provides NFS tuning recommendations such as dNFS mounts, writer-batch adjustment, increased NFSD processes, and required patches. It also documents driver commands for loading and inspecting ACFS, ADVM, and OKS drivers; Grid Infrastructure resource behavior; Oracle Restart alternatives using manual driver and filesystem management; plug-in metrics and file-ID APIs; tag naming, retrieval, listing, setting, and removal interfaces; and support-oriented diagnostics including filesystem debugging, state dumps, tracing open-file references, lock statistics, logging, metadata capture, and tuning. Read More: [Understanding Oracle ACFS Advanced Topics](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iv-advanced-topics/understanding-oracle-acfs-advanced-topics.html) ## Understanding Oracle ACFS Advanced Topics This page presents advanced Oracle ACFS diagnostics and administration, including lock-statistics reporting, memory and persistent logging, metadata collection and expansion, ACFS and ADVM tuning, I/O failure interpretation, and Grid Infrastructure patch management. It emphasizes privileged access, cautious use of diagnostic options, preserving metadata for support analysis, and verifying that active system drivers match the patched Grid Infrastructure software. Read More: [Understanding Oracle ACFS Advanced Topics](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iv-advanced-topics/understanding-oracle-acfs-advanced-topics.html) ## acfsutil log The `acfsutil log` command retrieves memory diagnostic logs and controls debugging for Oracle ADVM, ACFS, and Oracle Kernel Services. It can query or change log sizes and debug levels, target specific file systems, dump logs across cluster nodes, collect Hang Manager information, and temporarily raise diagnostics with `-o`; logs default to `oks.log`, and execution requires root or Oracle ASM administrator privileges. Read More: [acfsutil log](OSTMG 19c/Part IV Advanced Topics/19c/acfsutil log) ## acfsutil meta The `acfsutil meta` command collects Oracle ACFS metadata into a transferable record-oriented file for diagnostics, optionally using quick scanning, known-good metadata collection, online checking, Copy-on-Write storage, extent offsets, or an accelerator device. For reliable results, the file system should preferably be unmounted or left unmodified, output must be stored outside the source ACFS device, and large outputs may be compressed; collected files can later be expanded into sparse files for `fsck` or `acfschkdsk` analysis. Read More: [acfsutil meta](OSTMG 19c/Part IV Advanced Topics/19c/acfsutil meta) ## acfsutil plogconfig The `acfsutil plogconfig` command configures Oracle ACFS persistent diagnostic logging, including its directory, buffer size, timer interval, watermarks, maximum file size, and file count, and can query or terminate logging. It is intended for Oracle Support-directed diagnostics, requires root or Oracle ASM administrator privileges, and should be used only when configuration changes are specifically requested. Read More: [acfsutil plogconfig](OSTMG 19c/Part IV Advanced Topics/19c/acfsutil plogconfig) ## acfsutil tune The `acfsutil tune` command displays all ACFS tunable parameters, queries an individual parameter, or persistently changes a parameter on the local node. Changes take effect immediately and survive restarts, require root or Windows Administrator privileges, and may be used to adjust parameters such as maximum open or cached files and Hang Manager timing, although normal defaults should generally be retained unless performance or support requirements justify modification. Read More: [acfsutil tune](OSTMG 19c/Part IV Advanced Topics/19c/acfsutil tune) ## advmutil tune The `advmutil tune` command displays all Oracle ADVM parameter values, queries a selected parameter, or sets a new value for a privileged user. Parameters such as `deadlock_timer`, `resilver_power`, and `resilver_regio` affect ADVM behavior and should be changed cautiously, generally under Oracle Support guidance. Read More: [advmutil tune](OSTMG 19c/Part IV Advanced Topics/19c/advmutil tune) ## Understanding Oracle ACFS I/O Failure Console Messages Oracle ACFS reports I/O failures in the operating system event log using a structured message containing the error code, device, operation and transfer type, file entry, offset, length, impact scope, object type, operational context, snapshot status, object identifier, and internal code location. The file entry can be mapped to a file name with `acfsutil info fileid`, while internal context and code-location fields primarily support Oracle troubleshooting of hardware, device, metadata, and data-access failures. Read More: [Understanding Oracle ACFS I/O Failure Console Messages](OSTMG 19c/Part IV Advanced Topics/19c/Understanding Oracle ACFS I/O Failure Console Messages) ## Oracle Patching and Oracle ACFS Oracle ACFS is delivered with Oracle Grid Infrastructure and patched through OUI and OPatch along with Grid software. Standard patching updates the Grid home, system locations, and loaded drivers during controlled Clusterware restarts, whereas Zero Downtime Grid Infrastructure Patching initially updates only Grid-home content, leaving ACFS system components at their previous active version until they are explicitly loaded or the node reboots with a kernel change; active and available versions should therefore be checked across all nodes. Read More: [Oracle Patching and Oracle ACFS](OSTMG 19c/Part IV Advanced Topics/19c/Oracle Patching and Oracle ACFS) ## Overview of Oracle ACFS Patching Oracle ACFS components reside both in the Grid Infrastructure home and operating-system locations, so patch behavior depends on whether Zero Downtime Grid Infrastructure Patching is used. Standard procedures synchronize and load updated drivers during node-level Clusterware downtime, while zero-downtime procedures can leave active ACFS drivers and tools older than the newly patched Grid-home software; `crsctl query driver` and `acfsdriverstate version -v` identify the active, available, and local-node versions. Read More: [Overview of Oracle ACFS Patching](OSTMG 19c/Part IV Advanced Topics/19c/Overview of Oracle ACFS Patching) ## Updating Oracle Grid Infrastructure Files To load updated ACFS fixes into memory and install corresponding system tools, stop Clusterware on each node, run the Grid Infrastructure `rootcrs.sh -updateosfiles` procedure, and restart Clusterware with waiting enabled. A coordinated kernel-version reboot can perform the update automatically; afterward, active and available driver versions should match, confirming that the system is running the latest Grid-home software. Read More: [Updating Oracle Grid Infrastructure Files](OSTMG 19c/Part IV Advanced Topics/19c/Updating Oracle Grid Infrastructure Files) ## Verifying Oracle ACFS Patching Patch verification requires comparing OPatch inventory with the active and available ACFS driver versions reported by `crsctl query driver activeversion -all`, `crsctl query driver softwareversion -all`, and the local `acfsdriverstate version` command. With standard patching, these versions should agree; after zero-downtime patching, differences indicate that updated ACFS system software remains staged in the Grid home and has not yet been installed or loaded. Read More: [Verifying Oracle ACFS Patching](OSTMG 19c/Part IV Advanced Topics/19c/Verifying Oracle ACFS Patching) ## Configuring Oracle ACFS Snapshot-Based Replication Oracle ACFS snapshot-based replication, available from release 12.2, transfers differences between successive primary snapshots to a standby cluster over SSH, replacing the pre-12.2 continuous replication model. Configuration requires passwordless, bidirectional SSH trust between replication nodes, including appropriate user public keys, remote host keys, permissions, and optional VIP entries in known-hosts files. The acfsreplssh assistant can configure, verify, or remove keys, while manual procedures are also provided, including validation with acfsutil repl info. Windows deployments require supported Cygwin and SSH configuration, suitable domain-based replication users, correct service and file settings, and testing. Upgrades from earlier replication require Flex ASM and password-file preparation, Grid Infrastructure upgrades on both clusters, COMPATIBLE.ADVM set to 12.2, and either reinitialization or the staged acfsutil repl upgrade process; once started, the upgrade cannot be rolled back. Read More: [Configuring Oracle ACFS Snapshot-Based Replication](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iv-advanced-topics/configuring-oracle-acfs-snapshot-based-replication.html) ## Managing Oracle Flex ASM Oracle Flex ASM allows ASM instances to run separately from database servers, consolidating storage management while supporting local clients, remote clients with direct disk access, ACFS and ADVM through ASM proxy instances, and member-cluster access through Oracle IOServer. Flex ASM setup requires selecting dedicated, nonpublic ASM networks, for which ASM listeners are created automatically. Administration uses ASMCA, ASMCMD, CRSCTL, SQL\*Plus, and SRVCTL to inspect Flex ASM status and client connections, set ASM instance cardinality, relocate clients, manage ASM networks and listeners, configure network dependency behavior, and administer member clusters. The INSTANCE\_TYPE parameter identifies ASM proxy instances, while existing initialization parameters should be reviewed for the deployment. Read More: [Managing Oracle Flex ASM](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iv-advanced-topics/managing-oracle-flex-asm.html) ## Administering Oracle ASM Filter Driver Oracle ASM Filter Driver (ASMFD) is a kernel module that validates ASM disk I/O, blocks non-Oracle writes, and provides persistent disk management without rebinding devices after restarts. This page covers configuring ASMFD during or after Grid Infrastructure installation in clustered and standalone environments, including migration from ASMLIB, disk labeling and scanning, discovery-string management through AFD\_DISKSTRING and ASM\_DISKSTRING, status verification, and deconfiguration procedures. It also documents migration workflows for disk groups with or without OCR and voting files, cautions against manually altering ASM disks, explains platform and partition-table considerations, and describes the afdload and afddriverstate utilities for loading, unloading, and inspecting the driver. Read More: [Administering Oracle ASM Filter Driver](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iv-advanced-topics/administering-oracle-asm-filter-driver.html) ## Creating Database Files in Oracle ASM Using SQLPlus Oracle ASM allows SQL\*Plus to create and manage database files with minimal file-system configuration, typically using disk groups through initialization parameters and ASM-managed file naming. The page explains creating databases with data, recovery, control, undo, and redo files; creating permanent and temporary tablespaces with configurable size and autoextend behavior; multiplexing redo logs across disk groups; specifying ASM control files and handling file references differently with NORESETLOGS and RESETLOGS; and placing archived redo logs or recovery files in ASM disk groups using LOG\_ARCHIVE\_DEST, LOG\_ARCHIVE\_DEST\_n, and DB\_RECOVERY\_FILE\_DEST. Read More: [Creating Database Files in Oracle ASM Using SQLPlus](https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/part-iv-advanced-topics/creating-database-files-in-oracle-asm-using-sqlplus.html)