Private volumes and scratch volumes

To optimize tape storage, review the information about private volumes and scratch volumes. Use private volumes and scratch volumes appropriately.

Private volumes cannot be overwritten when a scratch mount is requested. You cannot check in a volume with scratch status when that volume is used by a storage pool, to export data, to back up a database or to back up to a backup set volume.

Partially written volumes are always private volumes. Volumes have a status of either scratch or private, but when IBM Spectrum Protect stores data on them, their status becomes private.

Table 1. Private volume and scratch volume uses
Type of volume When to use
Private volumes Use private volumes to regulate the volumes that are used by individual storage pools, and to manually control the volumes. To define private volumes, issue the DEFINE VOLUME command. For database restore, memory dumps, or loads, or for server import operations, you must specify private volumes.
Scratch volumes
In some cases, you can simplify volume management by using scratch volumes. You can use scratch volumes in the following circumstances:
  • When you do not need to define each storage pool volume.
  • When you want to take advantage of the automation of robotic devices.
  • When different storage pools share an automated library, and the storage pools can dynamically acquire volumes from the scratch volumes in the library. The volumes do not have to be preallocated to the storage pools.