|Oracle® Automatic Storage Management Administrator's Guide
11g Release 2 (11.2)
Part Number E16102-05
This chapter contains the following topics:
See Also:Oracle Database New Features Guide for a complete description of the new features in Oracle Database 11g release 2 (11.2)
Note:This functionality is available starting with Oracle Automatic Storage Management 11g Release 2 (126.96.36.199). For release 2 (188.8.131.52), Oracle ACFS encryption, replication, security, and tagging are available on Linux.
This section describes the Oracle Automatic Storage Management (Oracle ASM) 11g release 2 (184.108.40.206) new features:
Oracle ACFS security
Oracle ACFS security enables you to create realms to specify security policies for users and groups to determine access on file system objects. The Oracle ACFS security feature provides a finer-grained access control on top of the access control provided by the operating system.
Oracle ACFS security can utilize the encryption feature to protect the contents of realm-secured files stored in Oracle ACFS file systems.
Note:Oracle ACFS security is not supported if the file system has been replicated with Oracle ACFS replication.
Oracle ACFS encryption
Oracle ACFS encryption protects data in an Oracle ACFS file system in encrypted format to prevent unauthorized use of data in the case of data loss or theft.
Note:Encryption is not supported if the file system has been replicated with Oracle ACFS replication.
Oracle ACFS replication
This feature enables replication of Oracle ACFS file systems across the network to a remote site, providing disaster recovery capability for the file system.
This release of the feature supports only one standby file system for each primary file system.
Oracle ACFS replication is not supported if the file system has been encrypted with Oracle ACFS encryption.
Oracle ACFS replication is not supported if the file system has been prepared for Oracle ACFS security.
Oracle ACFS tagging
This feature provides a method for relating a group of files based on a common naming attribute assigned to these files called a tag name. Oracle ACFS Replication can use this tagging feature to select specific files with a unique tag name for replication to a different remote cluster site. This tagging option reduces the need to replicate an entire Oracle ACFS file system.
New configuration wizard for cluster configuration outside of software installation
This feature provides a wizard to configure an Oracle Grid Infrastructure environment after the installation has completed and has been tested.
For more information, refer to "Configuring Oracle Grid Infrastructure with the Configuration Wizard".
Oracle ACFS functionality on the Solaris operating system
This feature provides Oracle ACFS functionality on the Solaris operating system.
For more information, refer to "Oracle ACFS Command-line Tools for the Solaris Environment".
Oracle ACFS functionality on the AIX operating system
This feature provides Oracle ACFS functionality on the AIX operating system.
For more information, refer to "Oracle ACFS Command-line Tools for the AIX Environment".
Oracle ASM Configuration Assistant enhancements
These enhancements to ASMCA provide support for Oracle ACFS file system security and encryption.
For more information, refer to "Managing Security and Encryption for Oracle ACFS File Systems with Oracle ASM Configuration Assistant".
This section describes the Oracle Automatic Storage Management (Oracle ASM) 11g release 2 (220.127.116.11) new features:
Oracle Automatic Storage Management Cluster File System (Oracle ACFS)
Oracle Automatic Storage Management Cluster File System (Oracle ACFS) is a new multi-platform, scalable file system, and storage management design that extends Oracle ASM technology to support all of your application data in both single host and cluster configurations. Additionally, Oracle ACFS provides snapshot functionality for a point-in-time copy of an Oracle ACFS system.
For more information, see "Overview of Oracle ACFS".
Oracle ASM Dynamic Volume Manager
Oracle ASM Dynamic Volume Manager (Oracle ADVM) provides volume management services and a standard disk device driver interface to clients. File systems and other disk-based applications send I/O requests to Oracle ADVM volume devices as they would to other storage devices on a vendor operating system.
Oracle Automatic Storage Management Cluster File System (Oracle ACFS) is layered on Oracle ASM through the Oracle ADVM interface. With the addition of Oracle ADVM, Oracle ASM becomes a complete storage solution for both database and non-database file needs.
For more information, see "Overview of Oracle ASM Dynamic Volume Manager".
Oracle Automatic Storage Management Cluster File System Snapshots
An Oracle ACFS Snapshot is a point-in-time copy of a file system that can provide up to 63 snapshot images. Oracle ACFS Snapshot performs fast creation of persistent Oracle ACFS images at a specific point in time with very low overhead leveraging the Copy-on-Write (COW) technology.
Even as the file system changes, the snapshot does not, giving you the ability to view the file system as it was at the time the snapshot was created. Initially, snapshots are read-only, which preserves the point in time they captured.
For more information, see "About Oracle ACFS Snapshots".
Oracle ASM Configuration Assistant (ASMCA)
Oracle ASM Configuration Assistant provides a GUI interface for installing and configuring Oracle ASM instances, disk groups, volumes, and file systems.
In addition, the ASMCA command-line interface provides functionality for installing and configuring Oracle ASM instances, disk groups, volumes, and file systems in a non-GUI utility.
For more information about using Oracle ASM Configuration Assistant, see Chapter 11, "Oracle ASM Configuration Assistant".
This feature extends Oracle ASM Command Line Utility (ASMCMD) to provide full functionality, so that any operation that can be performed with SQL commands can be performed with ASMCMD. The added functionality includes the following areas:
Disk, failure group, and disk group operations
Disk group attribute operations
Oracle ASM File Access Control user and group operations
Oracle ASM instance operations
Oracle ASM volume operations
For more information about ASMCMD commands, see "Types of ASMCMD Commands".
Intelligent Data Placement
The Intelligent Data Placement feature enables you to specify disk regions on Oracle ASM disks to ensure that frequently accessed data is placed on the outermost (hot) tracks which provide higher performance.
For more information, see "Intelligent Data Placement".
Specifying the Sector Size for Disk Drives
Oracle ASM provides the capability to specify a sector size of 512 bytes or 4096 kilobytes with the
SECTOR_SIZE disk group attribute when creating disk groups. Oracle ASM provides support for 4 KB sector disk drives without a performance penalty.
For information about setting the sector size for disk drives, see "Specifying the Sector Size for Drives".
Disk Group Rename
renamedg tool enables you to change the name of a cloned disk group.
For information about renaming disk groups with
renamedg, see "Renaming Disks Groups".
Oracle ASM File Access Control
Oracle ASM on Linux and UNIX platforms implements access control on its files to isolate different database instances from each other and prevent accidental access that could lead to the corruption of data files. Oracle ASM implements new SQL statements and ASMCMD commands to grant, modify, and deny file permissions. The new security model and syntax is consistent with those that have been implemented for the objects represented in an Oracle database.
This feature enables multiple database instances to store their Oracle ASM files in the same disk group and be able to consolidate multiple databases while preventing an unauthorized database instance from accessing and overwriting files of a different instance.
For more information about Oracle ASM File Access Control, see "Managing Oracle ASM File Access Control for Disk Groups", "Managing Oracle ASM File Access Control with Oracle Enterprise Manager", and "ASMCMD File Access Control Commands".
Oracle Cluster Registry (OCR) and Voting Files stored in Oracle ASM
This feature enables storage of Oracle Cluster Registry (OCR) and the voting file in Oracle ASM disk groups. This functionality enables Oracle ASM to provide a unified storage solution, storing all the data for the clusterware and the database, without the need for third-party volume managers or cluster file systems.
For more information, see "Oracle Cluster Registry and Voting Files in Oracle ASM Disk Groups".
See Also:Oracle Clusterware Administration and Deployment Guide for information about administering voting files and Oracle Cluster Registry (OCR)
Oracle Restart enables the startup and automatic restart of single-instance Oracle Database through the Cluster Ready Services (CRS) component of Oracle Clusterware on a single server. This provides higher availability and automated management of single-instance Oracle Database and Oracle ASM instances.
For more information, see "Using Oracle Restart".
Oracle Database Administrator's Guide for information about configuring and administering Oracle Restart
Oracle Real Application Clusters Administration and Deployment Guide for information about automatically restarting single-instance databases residing on an Oracle RAC node
Oracle Enterprise Manager Support of Oracle ACFS
Oracle Enterprise Manager has enhanced Oracle ASM support to enable you to manage Oracle Automatic Storage Management Cluster File System (Oracle ACFS) technology and Oracle ASM Dynamic Volume Manager. These features operate as a comprehensive management solution to extend Oracle ASM technology to support all your application data files in database and non-database and in both single host and cluster configurations.
Oracle Enterprise Manager supports the following:
Create, modify, and delete Oracle ACFS
Monitor space usage and performance features of Oracle ACFS
Support Oracle ASM Dynamic Volume Manager features as required by Oracle ACFS
For more information about using Oracle Enterprise Manager to administer Oracle ASM, see Chapter 10, "Administering Oracle ACFS with Oracle Enterprise Manager".
Oracle Enterprise Manager Database Control Enhancements for Improved Oracle ASM Manageability
Oracle Enterprise Manager has been enhanced to manage Oracle ASM features, such as Oracle ASM File Access Control, OCR and voting files in Oracle ASM, disk resync, Oracle ASM rolling migrations, disk regions, and Oracle ASM manageability and infrastructure.
For more information about using Oracle Enterprise Manager to administer Oracle ASM, see Chapter 9, "Administering Oracle ASM with Oracle Enterprise Manager".
Oracle Enterprise Manager Oracle ASM Support Workbench
Oracle Enterprise Manager Oracle ASM Support Workbench has been enhanced to help diagnose and package incidents to Oracle Support Services for Oracle ASM instances. This feature extends the benefit of Oracle Enterprise Manager Support Workbench to Oracle ASM by helping you package all necessary diagnostic data for incidents.
For more information about using Oracle Enterprise Manager to administer Oracle ASM, see "Oracle ASM Support Workbench".
Oracle Database Administrator's Guide for information about viewing problems with Oracle Enterprise Manager Support Workbench
Oracle Database 2 Day DBA for information about accessing Oracle Enterprise Manager Support Workbench home page and viewing problems using Oracle Enterprise Manager Support Workbench
This section describes the Oracle Automatic Storage Management (Oracle ASM) 11g release 1 (11.1) new features:
This book is new for Oracle Database 11g release 1 (11.1) and it is the primary information source for Oracle Automatic Storage Management features.
Oracle ASM Fast Mirror Resync
Oracle ASM fast mirror resync quickly resynchronizes Oracle ASM disks within a disk group after transient disk path failures if the disk drive media is not corrupted. Any failures that render a failure group temporarily unavailable are considered transient failures. Disk path malfunctions, such as cable disconnections, host bus adapter or controller failures, or disk power supply interruptions, can cause transient failures.
The duration of a fast mirror resync depends on the duration of the outage. The duration of a resynchronization is typically much shorter than the amount of time required to completely rebuild an entire Oracle ASM disk group.
For more information about Oracle ASM fast mirror resync, see "Oracle ASM Fast Mirror Resync".
Oracle ASM Rolling Upgrade
You can now place an Oracle ASM Cluster in rolling upgrade mode, which enables you to operate with mixed Oracle ASM versions starting with Oracle Database 11g release 1 (11.1) and later. Consequently, Oracle ASM nodes can be independently upgraded or patched without affecting database availability.
For more information about Oracle ASM rolling upgrade, see "Using Oracle ASM Rolling Upgrade".
New SYSASM Privilege and OSASM operating system group for Oracle ASM Administration
This feature introduces a new SYSASM privilege that is specifically intended for performing Oracle ASM administration tasks. Using the SYSASM privilege instead of the SYSDBA privilege provides a clearer division of responsibility between Oracle ASM administration and database administration.
OSASM is a new operating system group that is used exclusively for Oracle ASM. Members of the OSASM group can connect as
SYSASM using operating system authentication and have full access to Oracle ASM.
For more information about the SYSASM privilege, see "Authentication for Accessing Oracle ASM Instances".
Oracle ASM Scalability and Performance Enhancements
Oracle ASM file extent management has been enhanced to improve performance and to use significantly less system global area (SGA) memory to store file extents. When Oracle ASM files increase in size, the size of each new extent also increases automatically so that fewer extent pointers are required to describe the file. This feature improves performance when accessing Oracle ASM files that are 20 GB and larger, up to 128 TB. Very large databases (VLDBs) often require these large file sizes. In addition, when you create new disk groups you now have multiple allocation unit (AU) size options, such as 1, 2, 4, 8, 16, 32, and 64. You might obtain significant performance improvements by selecting larger allocation units depending on the type of workloads (typically large sequential I/O) and storage system types.
For more information about scalability and performance enhancements, see "Extents".
Oracle ASM Command Line Utility (ASMCMD) Commands and Options
ASMCMD has the following new commands:
remap. In addition, you can use new options for the
For more information about new and enhanced ASMCMD commands, "Types of ASMCMD Commands".
Enhancements to SQL statements to manage Oracle ASM disk groups
DISKGROUP SQL statements have been enhanced with additional syntax options, including:
Syntax that sets various attributes of a disk group
Syntax for checking the consistency of disk groups, disks, and files in an Oracle ASM environment
Syntax options when mounting a disk group.
Syntax that takes a disk offline for repair and then brings it back online.
Syntax that drops a disk group that can no longer be mounted by an Oracle ASM instance.
For more information about administering disk groups with the
DISKGROUP SQL statements, see Chapter 4, "Administering Oracle ASM Disk Groups".
New Attributes for Disk Group Compatibility
To enable the new Oracle ASM features, you can use two new disk group compatibility attributes,
COMPATIBLE.ASM. These attributes specify the minimum software version that is required to use disk groups for the database and for Oracle ASM respectively. This feature enables heterogeneous environments with disk groups from both Oracle Database 10g and Oracle Database 11g. By default, both attributes are set to
10.1. You must advance these attributes to take advantage of the new features.
For more information about disk group compatibility, see "Disk Group Compatibility".
Oracle ASM Preferred Read Failure Groups
This feature is useful in extended clusters where remote nodes have asymmetric access with respect to performance. The feature enables more efficient use of network resources by eliminating the use of the network to perform read operations.
Oracle ASM in Oracle Database 10g always reads the primary copy of a mirrored extent set. In Oracle Database 11g, when you configure Oracle ASM failure groups it might be more efficient for a node to read from a failure group that is closest to the node, even if it is a secondary extent. You can configure your database to read from a particular failure group extent by configuring preferred read failure groups.
For more information about preferred read failure groups, see "Preferred Read Failure Groups".
Rebalance operations that occur while a disk group is in
RESTRICTED mode eliminate the lock and unlock extent map messaging between Oracle ASM instances in Oracle RAC environments, improving overall rebalance throughput.
For more information about Oracle ASM fast rebalance, see "About Restricted Mode".