Administrator's Guide


Volumes in Storage Pools

Volumes in storage pools contain backed-up, archived, or space-managed data from clients. Storage pools and their volumes are either random access or sequential access, depending on the device type of the device class to which the pool is assigned.

Random access storage pools are always associated with the DISK device class and all volumes in this type of storage pool have the same form.

Each volume defined in a sequential access storage pool must be of the same type as the device type of the associated device class. See Table 10 for the types of volumes associated with each device type and whether the type requires a recorded label on each volume.

Table 10. Volume Types

Device Type Volume Description Label Required
3590 IBM 3590 tape cartridge Yes
CARTRIDGE IBM 3480 or 3490 cartridge system tape Yes
FILE A file in the file system of the server machine No
SERVER One or more objects that are archived in the server storage No

Preparing Volumes for Random Access Storage Pools

For a random access storage pool, you must define volumes.

Task Required Privilege Class
Define volumes in any storage pool System or unrestricted storage
Define volumes in specific storage pools System, unrestricted storage, or restricted storage for those pools
Note:When you define a random access storage pool volume, it must occupy at least 1MB of space.
Performance tip:You may be able to improve throughput to disk by using the server option, FIXEDIOBUFSIZE. This option specifies the number of megabytes of virtual storage to be fixed when the server writes to or reads from disk storage pool volumes. If you specify a value greater than 0 for this option, the server fixes the I/O pages up to the number of megabytes specified for the duration of the session. You can specify a value from 0 to 64 for this option, meaning 0 to 64MB. A larger FIXEDIOBUFSIZE value may result in better performance throughput to Virtual Storage Access Method (VSAM) disk, but the larger value also requires more memory. This option also affects whether the server fixes pages for the database and recovery log. See Chapter 16, Managing the Database and Recovery Log. See Administrator's Reference for information about server options.

Create additional storage pool volumes by performing the following steps:

  1. Allocate and format the new volume by running one of two jobs, ANRFMT or ANRFMT2. If the SMS address space is not active, edit and run the ANRFMT job from the ASAMPLIB dataset. If the SMS address space is active, run the ANRFMT2 job.

    Running ANRFMT

    Edit the following parameters before running the job:

    For more information about the ANRFMT job, see Using the ANRFMT Job.

    Running ANRFMT2

    Ensure that you have installed the ANRFMT2 job in a procedure library. Enter the following command at the system console:

    s anrfmt,name=server.storage.pool003,mb=100,volser=WREN01
    

    For more information about the ANRFMT2 job, see Using the ANRFMT2 Job.

  2. Edit and run the ANRFMT or ANRFMT2 job again to allocate and format the second new storage pool volume as in the previous step. For example, if the name of your second new storage pool is server.storage.pool004, enter this name in the appropriate parameter fields.

  3. Assign the newly created storage pool volumes to the storage pools by entering the following commands:
    define volume backuppool  server.storage.pool003
    define volume archivepool server.storage.pool004
    

    See Step 2: Defining Database or Recovery Log Volumes for details about defining volumes to the server.

  4. If you have Tivoli Space Manager clients (HSM clients) that use the TSM server, you may also want to allocate and format additional volumes for the space management storage pool by using the ANRFMT or ANRFMT2 jobs. After you allocate and format the new volume, you can assign it to the space management storage pool.

    For example, if you named the new volume server.storage.pool005, enter the following command to assign it to the space management storage pool:

    define volume spacemgpool server.storage.pool005
    

Preparing Volumes for Sequential Access Storage Pools

You can define volumes in a sequential access storage pool or you can specify that the server dynamically acquire scratch volumes. You can also use a combination of defined and scratch volumes.

See the following sections:

Defining Storage Pool Volumes


Task Required Privilege Class
Define volumes in any storage pool System or unrestricted storage
Define volumes in specific storage pools System, unrestricted storage, or restricted storage for those pools

When you define a storage pool volume, you inform the server that the volume is available for storing backup, archive, or space-managed data.

For a sequential access storage pool, the server can use dynamically acquired scratch volumes, volumes that you define, or a combination.

Use defined volumes when you want to control precisely which volumes are used in the storage pool. Using defined volumes may be useful when you want to establish a naming scheme for volumes.

To define a volume named VOL1 in the ENGBACK3 tape storage pool, enter:

define volume engback3 vol1

Using Scratch Volumes

You do not have to define volumes in sequential access storage pools if you allow pools to use scratch volumes. Use the MAXSCRATCH parameter when you define or update the storage pool. Setting the MAXSCRATCH parameter to a value greater than zero lets the storage pool dynamically acquire volumes as needed. The server automatically defines the volumes as they are acquired. The server also automatically deletes scratch volumes from the storage pool when the server no longer needs them.

Before the server can use a scratch volume with other than FILE or SERVER device type, the volume must have a standard label.

The server tracks whether a volume being used was originally a scratch volume. Scratch volumes that the server acquired for a primary storage pool are deleted from the server database when they become empty. The volumes are then available for reuse by the server or other applications. For scratch volumes that were acquired in a FILE device class, the space that the volumes occupied is freed by the server and returned to the file system.

Scratch volumes in a copy storage pool are handled in the same way as scratch volumes in a primary storage pool, except for volumes with the access value of offsite. If an offsite volume becomes empty, the server does not immediately return the volume to the scratch pool. The delay prevents the empty volumes from being deleted from the database, making it easier to determine which volumes should be returned to the onsite location. The administrator can query the server for empty offsite copy storage pool volumes and return them to the onsite location. The volume is returned to the scratch pool only when the access value is changed to READWRITE, READONLY, or UNAVAILABLE.

Updating Storage Pool Volumes


Task Required Privilege Class
Update volumes System or operator

You can update the attributes of a storage pool volume assigned to a primary or copy storage pool. Update a volume to:

When using the UPDATE VOLUME command, be prepared to supply some or all of the information shown in Table 11.

Table 11. Information for Updating a Storage Pool Volume

Information Explanation
Volume name Specifies the name of the storage pool volume to be updated. You can specify a group of volumes to update by using wildcard characters in the volume name. You can also specify a group of volumes by specifying the storage pool, device class, current access mode, or status of the volumes you want to update. See the parameters that follow.
New access mode Specifies the new access mode for the volume (how users and server processes such as migration can access files in the storage pool volume). See Access Modes for Storage Pool Volumes for descriptions of access modes.

A random access volume must be varied offline before you can change its access mode to unavailable or destroyed. To vary a volume offline, use the VARY command. See Varying Disk Volumes Online or Offline.

If a scratch volume that is empty and has an access mode of offsite is updated so that the access mode is read/write, read-only, or unavailable, the volume is deleted from the database.

Location Specifies the location of the volume. This parameter can be specified only for volumes in sequential access storage pools.
Storage pool Restricts the update to volumes in the specified storage pool.
Device class Restricts the update to volumes in the specified device class.
Current access mode Restricts the update to volumes that currently have the specified access mode.
Status Restricts the update to volumes with the specified status (online, offline, empty, pending, filling, or full).
Preview Specifies whether you want to preview the update operation without actually performing the update.

An example of when to use the UPDATE VOLUME command is if you accidentally damage a volume, VOL1. You can change the access mode to unavailable so that the server does not try to write or read data from the volume. Enter the following command:

update volume vol1 access=unavailable

Access Modes for Storage Pool Volumes

Access to any volume in a storage pool is determined by the access mode assigned to that volume. You can change the access mode of a volume. The server can also change the access mode based on what happens when it tries to access a volume. For example, if the server cannot write to a volume having read/write access mode, the server automatically changes the access mode to read-only.

The access modes are:

Read/write
Allows files to be read from or written to a volume in the storage pool.

If the server cannot write to a read/write access volume, the server automatically changes the access mode to read-only.

If a scratch volume that is empty and has an access mode of offsite is updated so that the access mode is read/write, the volume is deleted from the database.

Read-only
Allows files to be read from but not written to a disk or tape volume.

If a scratch volume that is empty and has an access mode of offsite is updated so that the access mode is read-only, the volume is deleted from the database.

Unavailable
Specifies that the volume is not available for any type of access by the server.

You must vary offline a random access volume before you can change its access mode to unavailable. To vary a volume offline, use the VARY command. See Varying Disk Volumes Online or Offline.

If a scratch volume that is empty and has an access mode of offsite is updated so that the access mode is unavailable, the volume is deleted from the database.

Destroyed
Specifies that a primary storage pool volume has been permanently damaged. Neither users nor system processes (like migration) can access files stored on the volume.

This access mode is used to indicate an entire volume that should be restored using the RESTORE STGPOOL or RESTORE VOLUME command. After all files on a destroyed volume are restored to other volumes, the destroyed volume is automatically deleted from the database. See How Restore Processing Works for more information.

Only volumes in primary storage pools can be updated to destroyed.

You must vary offline a random access volume before you can change its access mode to destroyed. To vary a volume offline, use the VARY command. See Varying Disk Volumes Online or Offline. Once you update a random access storage pool volume to destroyed, you cannot vary the volume online without first changing the access mode.

If you update a sequential access storage pool volume to destroyed, the server does not attempt to mount the volume.

If a volume contains no files and the UPDATE VOLUME command is used to change the access mode to destroyed, the volume is deleted from the database.

Offsite
Specifies that a copy storage pool volume is at an offsite location and therefore cannot be mounted. Use this mode to help you track volumes that are offsite. The server treats offsite volumes differently, as follows:

You can only update volumes in a copy storage pool to offsite access mode. Volumes that have the device type of SERVER (volumes that are actually archived objects stored on another TSM server) cannot have an access mode of offsite.


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