HP XP P9500 Storage - Manual (Page 9)

HDD class and force another volume out of that parity group, the Auto Migration operation requires
a minimum of 20 percent difference in estimated disk usage between the two volumes. If the
difference in disk usage is less than 20 percent, the migration plan is considered an ineffective
strategy, and the volume is not migrated. The following figure illustrates this Auto Migration
operation.
Figure 6 Migrating a Volume Automatically Within the Same HDD Class
Automatic volume migration 9