This glossary focuses on terms specific to Oracle Hierarchical Storage Manager and StorageTek QFS Software and file systems. For industry standard definitions, please refer to the dictionary maintained by the Storage Networking Industry Association at http://www.snia.org/education/dictionary/.
All storage space that is user-referenced through an Oracle HSM file system. See online storage, nearline storage, and offsite storage.
A set of user- and/or group-owned storage that administrators use. Admin sets are typically created to administer storage for projects that involve users from several groups and span multiple files and directories.
Media that stores copies of the files in an Oracle HSM file system. Archival media can include removable tape cartridges, magneto-optical cartridges, disk file systems configured as archival volumes, and cloud storage volumes.
A collection of files that are copied to archival media together, using a common set of policies and parameters. Set membership determines the number of copies made, the parameters of the copying process, and the media used.
The archiver.cmd file defines archive sets by file system, directory location, size, and/or user and group ownership. See the archiver.cmd (4) man page for additional details.
The Oracle HSM program that manages the process of copying files to archival media. See the archiver (1m) man page for additional details.
Copying a group of files that are no longer resident in the disk cache from archival media back to the Oracle HSM disk cache when a user or application accesses any one member of the group. Associative staging insures that files that are used together are staged together. File owners can associate any files that reside in the same directory by setting the associative-staging attribute on the related files. See the staging (1) man page, staging, and disk cache for additional details.
The process of loading cartridges to verify their volume serial numbers (VSNs). For magneto-optical cartridges, the capacity and space information is determined and entered into the automated library's catalog.
A device that stores removable media cartridges, loads them into drives, and unloads them without operator intervention. An automated library contains cartridge storage slots, one or more drives, a transport mechanism for the cartridges, and, often, a mechanism for ingesting and exporting cartridges. See direct-attached automated library, network-attached automated library, robot, transport.
A snapshot of a collection of files for the purpose of preventing inadvertent loss. A backup includes both the file's attributes and associated data.
A bitmap representing each available block of storage on a disk and indicating whether the block is in use or free.
The size of the smallest addressable data unit on a block device, such as a magnetic tape cartridge or hard disk. The block size for a Linear Tape Open (LTO) cartridge is 256 kilobytes. For an Oracle StorageTek T10000 tape cartridge, the block size is 2048 kilobytes. For disk devices, block size is equivalent to sector size, which is typically 512 bytes.
Writing and reading data to storage media, such as magnetic tape or disk, via an intervening segment of host memory, called the buffer. When an application writes to the storage device, the host lets the required changes accumulate in memory before writing them out to the media in a single operation, a process called flushing the buffer. When an application reads from the media, the host reads more data from the media than the application requested and stores it all in memory, in case the application subsequently requests the additional data.
By consolidating a large number of application I/O requests into a smaller number of hardware I/O operations, buffering improves I/O performance and uses storage hardware more efficiently, even when applications send or request data in suboptimal amounts or at inconsistent rates. Compare direct I/O.
A container for data-storage media, such as magnetic tape or optical media. Also called a volume, a tape, a piece of media, or, loosely, a VSN. See volume, volume serial number (VSN).
The Oracle Hierarchical Storage Manager software's record of the removable media volumes in an automated library. Volumes are identified and tracked using a volume serial number. See volume serial number (VSN), historian.
Adjective describing a distributed computer application that divides work between servers that specialize in providing files or services and clients that request files and services when performing particular tasks.
Cloud storage that is accessed and managed as if it were a network-attached tape library containing a set of labeled media volumes. For additional information, see the cloud (7) man page.
Storage provided as an abstract, network service, without reference to any particular physical implementation or location. Cloud storage supplies users with an agreed level of service rather than a set of defined physical resources. Users and applications store and access data by addressing logical containers rather than physical locations.
A cloud library is the Oracle Hierarchical Storage Manager interface to cloud storage.
Data Integrity Validation (DIV)
Data Integrity Validation, a feature of Oracle StorageTek tape drives that works with the Oracle HSM software to calculate and compare checksums during I/O.
During write operations, Oracle HSM calculates a four-byte checksum for each data block and passes the checksum to the drive along with the data. The tape drive then recalculates the checksum and compares the result to the value supplied by Oracle HSM. If the values agree, the drive writes both the data block and the checksum to tape. Optionally, when the write operation is complete, Oracle HSM can ask the tape drive to rescan the data, recalculate checksums, and compare the results to the checksums stored on the tape.
During read operations, both the drive and Oracle HSM read a data block and its associated checksum from tape. Each recalculates the checksum from the data block and compares the result to the stored checksum. If checksums do not match at any point, the drive notifies Oracle HSM that an error has occurred.
In an Oracle HSM shared file system, a client that is connected to tape drives and performs tape I/O on behalf of the metadata server. See distributed I/O.
A configurable feature of Oracle HSM that provides specific error information for the hardware devices that support file systems.
Software that periodically monitors the presence of all manually mounted removable devices and detects the presence of mounted cartridges that can be requested by users or by other processes.
Access to files on archival media without preliminary staging to the disk cache. The -n (stage never) staging attribute marks files for direct access. See removable media file and the stage (1) man page for more information.
direct-attached automated library
An automated library that is connected directly to the host via a SCSI interface. Oracle HSM software can directly control SCSI-attached libraries.
Reading from and writing to a storage device without using memory buffers on the host. Direct I/O can improve performance when transferring large amounts of block-aligned, sequential data. But otherwise, buffered I/O generally provides the best results.
In QFS file systems, the minimum amount of contiguous space that each I/O operation consumes, regardless of the amount of data written. The disk allocation unit thus determines the minimum number of I/O operations needed when transferring a file of a given size. The DAU should always be a multiple of the block size of the disk device.
The size of the disk allocation unit varies depending upon the QFS device type selected and user requirements. The md device type uses dual-allocation units: the DAU is 4 kilobytes for the first eight writes to a file and then a user-specified 16, 32, or 64 kilobytes for any subsequent writes, so that small files are written in suitably small blocks, while larger files are written in larger blocks. The mr and striped group device types use a DAU that is adjustable in increments of 8 within the range [8-65528] kilobytes. Files are thus written in large, uniform blocks that can closely approximate the size of the large, uniformly sized files.
See block size.
In Oracle Hierarchical Storage Manager SAM-Remote configurations, the buffer on the SAM-Remote server host that is used for archiving data from the client to the server.
The disk-resident portion of an Oracle HSM file system where files are written, modified, and read. New and modified files are copied from the disk cache to archive media and may eventually be released from the disk. When users subsequently request non-resident files, the files are staged (copied) from the archival media to the disk. Individual disk partitions or an entire disk can be used as disk cache.
The maximum or minimum level of disk cache utilization, as defined by an administrator. The releaser controls disk cache utilization based on these predefined disk space thresholds. See high-water mark, low-water mark, and releaser.
Writing a file across several disks, thereby improving access performance and increasing overall storage capacity. See also striping.
A feature of Oracle Hierarchical Storage Manager that lets the metadata server of a shared QFS file system delegate tape I/O to file system clients that are connected to tape drives. This reduces loads on the server and makes more efficient use of drives and SAN bandwidth. See data mover.
A electromechanical mechanism for transferring data to and from a removable-media volume, such as a magnetic tape cartridge.
An electromechanical, magnetic hard disk drive.
A solid-state device that emulates a disk drive. See solid-state device.
An array within a file's inode that defines the disk location of each data block assigned to the file.
In Oracle HSM and QFS file-system configurations, a group of physical devices that function as a single logical devices, such as a set of data and metadata disks or an automated library and its associated drives.
The ANSI standard that specifies high-speed serial communication between devices. Fibre Channel is used as one of the bus architectures in SCSI-3.
In the Oracle HSM archiver.cmd file, archiver and releaser directives that are specific to a particular file system. File system directives follow global directives and include all directives between an fs = filesystem-specifier directive and the next fs = directive or the end of the file. File system directives override any global directives that may also apply. See the archiver.cmd (4) man page for details.
File Transfer Protocol, a network protocol for transferring files between two hosts. For a more secure alternative, see sftp.
In the Oracle HSM archiver.cmd file, archiver and releaser directives that apply to all file systems. Global directives appear before the first fs = filesystem-specifier directive. See the archiver.cmd (4) man page for details.
In a disk quota, the amount of time that the file system allows the total size of files belonging to specified user, group, and/or admin sets to exceed the soft limit specified in the quota.
High-Availability Clients Outside the Cluster, the failover configuration for the metadata servers of a shared QFS file system that includes clients.
In an HA_COTC configuration, the file system is shared between active and potential QFS metadata servers and file-system clients. The metadata servers are hosted on a two-node, failover cluster. Clients are not hosted on cluster nodes. Solaris Cluster thus software ensures that the metadata servers remain available so that clients can access metadata and obtain I/O licenses. But clients are not configured for failover and cannot therefore compromise the integrity of the file system following a failure.
High Availability QFS, the failover configuration that insures that a QFS unshared, standalone file system remains accessible in the event of a host failure.
In an HA-QFS configuration, the file system is configured on both nodes of a two-node cluster managed by Solaris Cluster software. At any given time, only one node mounts the QFS file system. If the node that is mounting the file system fails, the clustering software automatically initiates fail over and re-mounts the file system on the remaining node.
High-Availability Oracle Hierarchical Storage Manager, the failover configuration for an archiving QFS file system.
In an HA-SAM configuration, Oracle Solaris Cluster software maintains the availability of the file system by insuring that the QFS metadata server and the Oracle Hierarchical Storage Manager application continue to operate even if a server host fails. The file system is shared between active and potential QFS metadata servers hosted on a two-node cluster that is managed by Solaris Cluster software and Data Services.
In a quota, the amount of time that the file system allows the total size of files belonging to specified user, group, and/or admin set IDs to exceed the soft limit specified in the quota. See quota, admin set, soft limit.
The percentage disk-cache utilization at which Oracle HSM starts the releaser process, deleting previously archived files from disk. A properly configured high-water mark insures that the file system always has enough space available for new and newly staged files. For more information, see the sam-releaser (1m) and mount_samfs (1m) man pages. Compare low-water mark.
In a removable media library that is part of an archiving file system, the percentage media-cache utilization at which Oracle HSM starts the recycler process. Recycling empties partially full volumes of current data so that they can replaced by new media or relabeled.
The Oracle HSM historian is a catalog of volumes that have been exported from the automated media libraries defined in the /etc/opt/SUNWsamfs/mcf file. By default, it is located at /var/opt/SUNWsamfs/catalog/historian on the Oracle HSM file-system host. For additional information, see catalog and the historian (7) man page.
The hosts.filesystem-name file that identifies the hosts that can mount a shared QFS file system. See the hosts.fs (4) man page for details.
A disk block that contains a list of storage blocks. Oracle HSM and QFS file-system metadata can contain up to three levels of indirect blocks. A first-level indirect block contains a list of blocks used for data storage. A second-level indirect block contains a list of first-level indirect blocks. A third-level indirect block contains a list of second-level indirect blocks.
An index node, a 512-byte metadata structure that defines a file for the file system. An inode describes all the attributes associated with a file other than the name. The attributes include ownership, access, permissions, size, and the location of the file.
In a QFS file system, a metadata file called .inodes that contains the inode structures for all files resident in the file system.
The program that provides basic operating system facilities. The UNIX kernel creates and manages processes, provides functions to access the file system, provides general security, and supplies communication facilities.
In a shared QFS file system, a function that grants a client permission to perform an operation on a file for a specified period of time. The metadata server issues leases to each client. Leases can be renewed as necessary.
See automated library.
See catalog.
An application programing interface (API) library that lets applications manipulate Oracle Hierarchical Storage Manager operations and files stored in StorageTek QFS file systems. With the libsam library, software applications that run on the file-system metadata server can access and manipulate file systems using local function calls. See the intro_libsam (3) and rest_libsam (3) man pages for details. Compare libsamrpc, rest_libsam.
An application programing interface (API) library that lets applications manipulate Oracle Hierarchical Storage Manager operations and files stored in StorageTek QFS file systems. The libsamrpc library makes remote procedure calls, so calling applications can run on any host on the network. It supports a subset of the libsam functions. Compare libsam, rest_libsam.
Linear Tape File System (LTFS)
An open standard for file systems on magnetic tape media. LTFS provides directory and file metadata that let users and applications use data as if it were stored on magnetic or solid-state disk.
A QFS file system that is not shared with other hosts.
A file system that is installed on a server for use by the operating system.
A file system that is installed on one node of a Solaris Cluster system and is not made highly available.
In an archiving file system, the percentage disk-cache utilization at which Oracle HSM stops the releaser process and stops deleting previously archived files from disk. A properly configured low-water mark insures that the file system retains as many file in cache as possible, for best performance, while making space available for new and newly staged files. For more information, see the sam-releaser (1m) and mount_samfs (1m) man pages. Compare high-water mark.
A Logical Unit Number, a logical partition of a physical device that is used as if it were an independent device.
The Master Configuration File that defines QFS file systems, data and metadata devices, and Oracle HSM archival data devices.
Material that stores data. Common storage media include magnetic tape, magnetic disks, solid-state devices, cloud services, and optical disks.
Copying files from one type or generation of archival tape media to a different type or a newer generation of the same type.
Copying files from old, worn archival tape media to new, replacement media.
A feature of Oracle Hierarchical Storage Manager 6.1 and later that automates the above processes.
Literally, data about data. In a file system, metadata is information about files and directories. It includes the locations of each file's data on storage media, file attributes such as file type (directory, regular file, character special file, block special file, etc), modification times, ownership, access permissions, and checksums. See inode, indirect block.
For additional details, see the Oracle HSM sls (1) and Solaris ls (1) man pages.
In an Oracle HSM high-performance (type ma) file system, a dedicated storage device type (type mm) that stores only file system metadata. See the mcf (4) man page.
You can use solid-state disk, electromechanical magnetic disk, or hardware or software mirrored devices as metadata devices.
The host that controls Oracle Hierarchical Storage Manager and StorageTek QFS file systems. The metadata server manages the file-system metadata, maintains configuration information for file systems and related processes, such as archiving, participates in file-system I/O, and, in shared configurations, makes the file system available to clients.
Only one metadata server can be active at a time. But, in shared configurations, you can configure some or all clients as standby, potential metadata servers that can be activated should the active server fail or require disruptive maintenance.
An Oracle HSM file system configuration in which all file system hosts can read files but only one host can write them. For more information, see the mount_samfs (1m) man page.
Removable media storage that requires robotic mounting before it can be accessed. Nearline storage is usually less expensive than online storage, but it takes somewhat longer to access. See automated library.
network-attached automated library
A library that is controlled by a software package supplied by the vendor. A parameter file identifies network-attached libraries to the Oracle HSM software, and a special Oracle HSM media changer daemon provides the interface to the vendor software. Oracle StorageTek ACSLS software controls Oracle StorageTek network-attached libraries. See automated library.
Network File System, a file system that provides transparent access to remote file systems on heterogeneous networks.
Storage that is immediately available. See disk cache.
A common abbreviation for Oracle Hierarchical Storage Manager.
An adjective describing a QFS file system that is configured for archiving and managed by Oracle HSM software.
The process of reserving a contiguous amount of space on the Oracle HSM disk cache for writing a file. Preallocation can be specified only for a file that is size zero. For more information, see the setfa (1) man page. See disk cache.
A QFS file system, an Oracle UNIX file system that offers high performance and high capacity. QFS file systems can be used on their own or with Oracle Hierarchical Storage Manager.
The StorageTek QFS product, which includes the file system without the Oracle Hierarchical Storage Manager software.
See samfsdump (qfsdump).
The amount of storage resources that specified user, group, or admin sets are allowed to consume. See hard limit and soft limit.
Redundant Array of Independent Disks, a disk technology that uses several independent disks to reliably store files. Depending on the architecture, it can protect against data loss should one or more disks fail and can provide higher throughput than individual disks.
A compressed file that stores a point-in-time backup copy of the metadata for a Oracle HSM file system.
In the event of a data loss—anything from accidental deletion of a user file to catastrophic loss of a whole file system—an administrator can recover to the last known-good state of the file or file system almost immediately by locating the last recovery point at which the file or file system remained intact. The administrator then restores the metadata recorded at that time and either stages the files indicated in the metadata to the disk cache from archival media or, preferably, lets the file system stage files on demand, as users and applications access them. See samfsdump (qfsdump).
An Oracle HSM utility that reclaims space when an archival tape volume is largely filled with stale copies (copies that no longer reflect the current state of the file). The recycler moves any remaining current file copies to other media and then relabels the volume. The relabeled volume can then be over-written with new files.
The process of moving current files from an archival media volume and relabeling the media for re-use. For details, see the sam-recycler (1m), recycler.cmd (1m), and recycler.sh (1m) man pages.
A string of characters in a standardized pattern-matching language that is designed for searching, selecting, and editing other character strings, such as file names and configuration files. For full details of the regular expression syntax used in Oracle HSM file-system operations, see the Solaris regex and regcmp man pages.
The priority according to which the Oracle HSM releaser deletes a file from the file disk cache once the file has been successfully archived. See the sam-releaser (1m) man page for details.
A Oracle HSM component that identifies archived files and releases their disk cache copies, thus making more disk cache space available. The releaser automatically regulates the amount of online disk storage according to high and low thresholds. See the sam-releaser (1m) and releaser.cmd (4) man page for details.
See RPC.
In an Oracle HSM file system, a special type of user file that can be accessed directly from where it resides on a removable media cartridge, such as magnetic tape or optical disk cartridge. See direct access.
Representational state transfer, the style of software architecture pioneered by the World Wide Web. REST emphasizes the roles of components, their interactions, and the ways that they represent data, rather than the internal implementation of components. Typical REST applications communicate via Hypertext Transfer Protocol (HTTP). REST is an alternative to RPC. See RPC.
An application programing interface (API) that lets applications control Oracle Hierarchical Storage Manager operations and access files stored in StorageTek QFS file systems. The rest_libsam library provides a lightweight REST interface that operates over an authenticated HTTPS connection. It is implemented on top of the existing libsam library and supports a subset of the libsam functions. Compare libsam, libsamrpc.
An automated library component that moves cartridges between storage slots and drives. Also called a transport.
A data access method in which entire files are written to logical disks in a sequential fashion. When a single file is written to disk, the entire file is written to the first logical disk. The second file is written to the next logical disk, and so on. The size of each file determines the size of the I/O. See also disk striping and striping.
Remote procedure call, a mechanism that lets a client application execute subroutines that run under an independent server application.
A common abbreviation for Storage Archive Manager, the former name of the Oracle Hierarchical Storage Manager product.
An Oracle HSM client-server configuration that lets an Oracle HSM metadata server access an automated tape library that is controlled by another Oracle HSM metadata server. The client is configured with pseudodevices that represent the devices that the server makes available and uses a specified subset of the archive media on the server.
A common abbreviation for older versions of the Oracle Hierarchical Storage Manager product.
An adjective describing a QFS file system that is configured for archiving and managed by Oracle HSM software.
An Oracle HSM command that backs up file system metadata to a dump file. See recovery point.
If the Oracle Hierarchical Storage Manager packages are not installed, the command is called qfsdump.
A program that restores inode and directory information from a recovery point. See samfsdump (qfsdump), recovery point.
Solaris Cluster-Oracle Real Application Cluster (SC-RAC), a high-availability Oracle Database solution that use QFS file systems.
In an SC-RAC solution, Oracle RAC software coordinates I/O requests, distributes workload, and maintains a single, consistent set of database files for multiple Oracle Database instances running on the nodes of a cluster. In the SC-RAC configuration, Oracle Database, Oracle Real Application Cluster (RAC), and QFS software run on two or more of the nodes of a cluster managed by Oracle Solaris Cluster software. One node is configured as the metadata server (MDS) of a QFS shared file system. The remaining nodes are configured as potential metadata servers that share the file system as clients. If the active metadata server node fails, Solaris Cluster software automatically activates a potential metadata server on a healthy node and initiates failover. Since the QFS file system is shared and already mounted on all nodes, access to the data remains uninterrupted.
Small Computer System Interface, an electrical communication specification commonly used for peripheral devices such as disk and tape drives and automated libraries.
Moving the read/write heads of a disk device from one disk location to another during random-access I/O operations.
Secure File Transfer Protocol, a secure implementation of ftp. See ssh.
When you create a shared file system, the system copies information from the hosts file to the shared hosts file on the metadata server. You update this information when you issue the samsharefs -u command
Small Computer System Interface
See SCSI.
In a quota, the maximum amount of storage space that a specified user, group, and/or admin set IDs can fill for an indefinite period. Files can use more space than the soft limit allows, up to the hard limit, but only for a short grace period defined in the quota. See grace period, hard limit, quota, admin set.
A storage device that uses electronically rewritable, non-volatile, NAND flash memory as the storage medium, such as a SAS-attached, solid-state disk drive (SSD).
Solid-state drives can provide significantly higher inputs and outputs per second (IOPS) and significantly lower latency compared to traditional magnetic hard drives. They are thus particularly good choices for use as the metadata devices of Oracle Hierarchical Storage Manager and StorageTek QFS, high-performance, ma file systems.
Secure Shell, an encrypted network protocol that allows secure, remote command-line login and command execution.
In Oracle HSM file systems, the process of copying an archived file that is no longer resident in the disk cache from archival storage back to the disk cache. See the staging (1) and stager.cmd (4) man pages, disk cache, and associative staging for additional information.
In an automated library, the storage bays that hold media cartridges that are not mounted in drives.
During striped device access, the number of disk allocation units (DAUs) that a QFS file system writes before moving to the next device in the stripe, as specified by the stripe= mount option.
In a QFS file system, a collection of devices configured as a single logical device of type gXXX. See the mcf (4) man page for additional information.
Writing files to multiple devices in parallel, so that each file is spread across all the devices.
QFS file systems support two types of striping:
Hard striping is a permanent feature of the file system that you enable when you specify striped group (type gXXX) devices in the Master Configuration File (mcf) entries that define the file system.
Soft striping is an optional feature that enable or disable when you mount the file system with the stripe= mount parameter.
Compare round-robin.
A Solaris Cluster Data Services resource type that supports failover for the Oracle Hierarchical Storage Manager application. SUNW.hasam is included with the Oracle HSM software. See HA-SAM.
A Solaris Cluster Data Services resource type that manages failover of a server's local storage, so that critical state and dynamic configuration information remains available. SUNW.HAStoragePlus is included in the Solaris Cluster software as a standard resource type. See HA-QFS, HA-SAM.
A Solaris Cluster Data Services resource type that supports failover for the metadata servers of a high-availability, StorageTek QFS file system. SUNW.qfs is included with the Oracle Hierarchical Storage Manager and StorageTek QFS software. See HA-QFS, HA-SAM, and HA-COTC.
A data structure in the file system that defines the basic parameters of the file system. The superblock is written to all partitions in the storage family set and identifies the partition's membership in the set.
Transmission Control Protocol/Internet Protocol. The internet protocols responsible for host-to-host addressing and routing, packet delivery (IP), and reliable delivery of data between application points (TCP).
Quota software that keeps track of the period starting when a user reaches a soft limit and ending when the hard limit is imposed on the user.
See robot.
The vfstab file contains mount options for the file system. Mount options specified on the command line override those specified in the /etc/vfstab file, but mount options specified in the /etc/vfstab file override those specified in the samfs.cmd file.
On storage media, a single, accessible, logical storage area, usually addressed by a volume serial number (VSN) and/or volume label. Storage disks and magnetic tape cartridges can hold one or more volumes. For use, volumes are mounted on a file system at a specified mount point. See volume serial number (VSN), mount point.
A magnetic tape cartridge that holds a single logical volume. See cartridge.
On a random-access disk device, a file system, directory or file that is configured and used as if it were a sequential-access, removable-media cartridge, such as a tape.
A capability that enables the system to span a single file over multiple volumes. Volume overflow is useful for sites using very large files that exceed the capacity of their individual cartridges.
A serial number assigned to a tape or disk storage volume. A volume serial number can consist of up to six uppercase, alphanumeric characters, must start with a letter, and must identify the volume uniquely within a given context, such a tape library or partition. The volume serial number is written on the volume label.
Loosely, a specific storage volume, especially a removable media cartridge. See cartridge, volume.