Tivoli Storage Manager for Windows Administrator's Guide


Overview: Volumes in Storage Pools

Storage pool volumes are the physical media that are assigned to a storage pool. Some examples of volumes are:

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 Pool Volumes

Random access storage pools consist of volumes on disk. Random access storage pools are always associated with the DISK device class. A volume in a random access storage pool is a fixed-size file that is created when you define a volume for the storage pool. See Preparing Volumes for Random Access Storage Pools.

Sequential Access Storage Pool Volumes

Volumes in sequential access storage pools include any supported device type to which the server writes data sequentially. Some examples of sequential access volumes are:

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 14 for the type of volumes associated with each device type.

For preparing sequential access volumes, see Preparing Volumes for Sequential Access Storage Pools.

Table 14. Volume Types

Device Type Volume Description Label Required
3570 IBM 3570 tape cartridge Yes
3590 IBM 3590 tape cartridge Yes
4MM 4mm tape cartridge Yes
8MM 8mm tape cartridge Yes
DLT A digital linear tape Yes
DTF A digital tape format (DTF) tape Yes
FILE A file in the file system of the server machine No
GENERICTAPE A tape that is compatible with the drives that are defined to the device class Yes
OPTICAL A two-sided 5.25-inch rewritable optical cartridge Yes
QIC A 1/4-inch tape cartridge Yes
REMOVABLEFILE A file on a removable medium. If the medium has two sides, each side is a separate volume. Yes
SERVER One or more objects that are archived in the server storage of another server No
WORM A two-sided 5.25-inch write-once optical cartridge Yes

Scratch Volumes Versus Defined Volumes

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. What you choose depends on the amount of control you need over individual volumes.

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.

Use scratch volumes to enable the server to define a volume when needed and delete the volume when it becomes empty. Using scratch volumes frees you from the burden of explicitly defining all of the volumes in a storage pool.

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.

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

To prepare a volume for use in a random access storage pool, you can use the Formatter in the TSM Server Utilities graphical user interface. The Formatter panels guide you through the steps you need to take. If you choose not to use the Formatter, you can instead define the volume. For example, you want to define a 21MB volume for the BACKUPPOOL storage pool. You want the volume to be located in the path c:\program files\tivoli\tsm\server and named stgvol.001. Enter the following command:

define volume backuppool 'c:\program files\tivoli\tsm\server\stgvol.001'
  formatsize=21

If you do not specify a full path name for the volume name, the command uses the current path.

Tips:

  1. For performance reasons, allocate storage pool volumes on disk drives that reside on the TSM server machine, not on remotely mounted file systems.

  2. The file system where storage pool volumes are allocated can have an effect on performance and reliability. For better performance in backing up and restoring large numbers of small files, allocate storage pool volumes on a FAT file system. To take advantage of the ability of the operating system to recover from problems that can occur during I/O to a disk, allocate storage pool volumes on NTFS.

Preparing Volumes for Sequential Access Storage Pools

For sequential access storage pools with a FILE or SERVER device type, no labeling or other preparation of volumes is necessary.

For sequential access storage pools with other than a FILE or SERVER device type, you must prepare volumes for use. When the server accesses a sequential access volume, it checks the volume name in the header to ensure that the correct volume is being accessed. To prepare a volume:

  1. Label the volume. Table 14 shows the types of volumes that require labels. You must label those types of volumes before the server can use them.

    See Labeling Media.

    Tip:When you use the LABEL LIBVOLUME command with drives in an automated library, you can label and check in the volumes with one command.
  2. For storage pools in automated libraries, use the CHECKIN LIBVOLUME command to check the volume into the library. See Checking Media into Automated Library Devices.
  3. If you have not allowed scratch volumes in the storage pool, you must identify the volume, by name, to the server. For details, see Defining Storage Pool Volumes.

    If you allowed scratch volumes in the storage pool by specifying a value greater than zero for the MAXSCRATCH parameter, you can let the server use scratch volumes, identify volumes by name, or do both. See Using Scratch Volumes for information about scratch volumes.

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.

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 storage 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 a device type other than FILE or SERVER, the volume must have a label. See Preparing Volumes for Sequential Access Storage Pools.

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:

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

update volume vol1 access=unavailable

When using the UPDATE VOLUME command, be prepared to supply some or all of the information shown in Table 15.

Table 15. Information for Updating a Storage Pool Volume

Information Explanation
Volume name

(Required)

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.

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 an access mode of 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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