HP StorageWorks XP10000 Disk Array - Manual (Page 17)

17
Figure 1-9 Migration Between Two External Storage Subystems
1-3 How Migration Works
Tiered Storage Manager allows you to migrate data located on a volume within the scope eligible for migration
without being aware of the change in LDEV number. After performing a migration, Tiered Storage Manager
changes the LDEV number automatically so that you do not have to change the access path to the host, which
prevents any interruption of an application service. Tiered Storage Manager migrates data in units of volumes.
You can migrate data between any storage subsystems as long as they are within the migration scope.
Migration consists of five processing steps:
1. After you create a migration task, you reserve a migration target volume. The reserved volume is not
accessible from a host.
2. When the execution of a migration task starts, Tiered Storage Manager copies data from the migration
source volume to the migration target volume
3. Tiered Storage Manager switches the LDEV number of the migration source volume with the LDEV
number of the migration target volume. A volume reservation is performed for an LDEV number. Thus,
the volume reservation moves from the migration source volume to the migration target volume just as
the LDEV numbers are switched
4. The volume reservation is removed. A volume reservation is also removed when a migration task is
canceled, or a migration task fails to execute. If removal of the volume reservation fails, refresh the
storage domain to remove it.
5. Tiered Storage Manager erases the data from the migration source volume when you select that option.
Figure 1-10 shows the relationship between volumes and LDEV numbers in volume reservation, LDEV number
switching, and data erasure
Using Tiered
Storage
Manage
r