Controlling tape storage operations

Device class definitions for tapes include parameters that allow you to control storage operations.

How IBM Storage Protect fills volumes
The DEFINE DEVCLASS command has an optional ESTCAPACITY parameter that indicates the estimated capacity for sequential volumes that are associated with the device class. IBM Storage Protect uses the estimated capacity of volumes to determine the estimated capacity of a storage pool, and the estimated percent utilized.
Specifying the estimated capacity of tape volumes
IBM Storage Protect also uses estimated capacity to determine when to begin the reclamation of storage pool volumes.
Specifying recording formats for tape media
You can specify the recording format that is used by IBM Storage Protect to write data to tape media. If you plan to mix generations of drives, or different drive types, within a library, you must specify a recording format for each drive generation and each drive type. In this way, the server can differentiate between the drive generations and drive types.
Associating library objects with device classes
A library contains the drives that can be used to mount the volume. Only one library can be associated with a device class. However, multiple device classes can reference the same library.
Controlling media-mount operations for tape devices
By using device class definitions, you can control the number of mounted volumes, the amount of time a volume remains mounted, and the amount of time that the IBM Storage Protect server waits for a drive to become available.
Preempting operations
The server can preempt server or client operations for a higher priority operation when a mount point is in use and no others are available, or access to a specific volume is required. When an operation is preempted, it is canceled.
Impacts of device changes on the SAN
The SAN environment can shift dramatically due to device or cabling changes. The dynamic nature of the SAN can cause static definitions to fail or become unpredictable.
Displaying device information
You can display information about devices that are connected to the server by using the device information utility (tsmdlst).
Write-once, read-many tape media
Write-once, read-many (WORM) media help to prevent accidental or deliberate deletion of critical data. However, IBM Storage Protect imposes certain restrictions and guidelines to follow when you use WORM media.
Troubleshooting problems with devices
You can troubleshoot errors that occur when you configure or use devices with IBM Storage Protect.

Parent topic: Implementation of a tape-based data protection solution