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 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.
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 7 for the type of volumes associated with each device type.
For preparing sequential access volumes, see Preparing Volumes for Sequential Access Storage Pools.
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 |
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.
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 Disk Volume wizard in the TSM Console. 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:
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:
See Labeling Media.
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.
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
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.
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 8.
Table 8. 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 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:
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.
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.
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.
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.
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.