Transparent recall processing

Transparent recall processing automatically returns a migrated file to its originating local file system when you access it. After the file is recalled, the space management client leaves the copy of the file in IBM Storage® Protect server storage. The file becomes a premigrated file because an identical copy exists both on your local file system and in IBM Storage Protect server storage. If you do not modify the file, it remains premigrated until it again becomes eligible for migration.

A transparent recall process waits for a tape drive to become available. If you back up and migrate data to tape volumes in the same library, make sure that there are always some tape drives available for space management. You can achieve tape drive availability by limiting the number of tape drives that can be used simultaneously by backup and archive operations. Specify a number for the mountlimit that is less than the total number of drives available in the library. Using disk storage as your primary storage pool for space management might, depending on the average size of your files, result in a better performance than using tape storage pools.

For information about the mountlimit option of the define devclass command, see the IBM Storage Protect Administrator's Reference for your operating system.

If you modify a recalled file, it becomes a resident file. The next time your file system is reconciled, the space monitor daemon marks the stored copy for expiration.