Migration types
The space management client provides automatic and selective migration. Automatic migration is triggered by space-usage thresholds (threshold migration) or an out-of-space condition (demand migration).
Automatic migration monitors space usage and automatically
migrates eligible files according to the options and settings that
you select. The space management client provides
two types of automatic migration: threshold migration and demand migration.
- Threshold migration
- Threshold migration maintains a specific level of free space on
your local file system. When space usage reaches the high threshold
that you set for your file system, eligible files are migrated to IBM Storage® Protect server storage
automatically. When space usage drops to the low threshold that you
set for your file system, file migration stops.
On IBM® Storage Scale file systems, you can use the IBM Storage Scale policy engine to monitor space thresholds and search for migration candidates.
For information about configuring IBM Storage Scale integration with the space management client, see Technote 7018848.
- Demand migration
- Demand migration responds to an out-of-space condition on your local file system. Demand migration starts automatically if your file system runs out of space. For HSM on AIX JFS2, as files are migrated, space becomes available on your file system. The process or event that caused the out-of-space condition continues. On GPFS™ file systems, the process receives an out-of-space (ENOSPC) return code and stops.
Selective migration moves specific files from your local file system to IBM Storage Protect server storage. You specify the files to migrate. Migration is not triggered automatically by file-system free space.