HP NonStop G-Series - Manual (Page 86)

Migration Guidelines
HP NonStop Storage Management Foundation User's Guide—523562-008
4-14
Migrating to a New System by Using Volume Mode
Backup
Reference Manual. For information on changing the system name in an SMF catalog,
contact your service provider.
After you have attached the disks to the new system, the data may remain on those
disks or be moved to new disks. In either case, the process for migrating the data to
SMF is identical to the procedures for migrating data on an existing system outlined in
the preceding sections.
Migrating to a New System by Using Volume Mode Backup
While file mode BACKUP and RESTORE is the preferred method of moving data from
one system to SMF virtual disks on another system, volume mode BACKUP and
RESTORE can sometimes be required. Such situations are if the data to be moved is
not online and exists only on a set of volume mode backups, or if only limited time is
available on the existing system for doing backups and only volume mode backups can
be completed in the allotted time.
The basic approach is to use an extra disk to first restore the volume mode backup,
and then move the data onto the SMF virtual disks using the procedures outlined in
Moving Data From Physical Volumes to Virtual Disks on page 4-12. After the data has
been moved onto the virtual disks, the extra disk can be removed from the SMF pool,
relabelled, and used to restore the next volume mode backup.
Pool Consolidation
In some migration scenarios, it might make sense to first migrate the data into small
pools and later consolidate those pools into larger pools. For example, if it is important
for some period of time to preserve the option of falling back to the original
configuration by using SMREVERT, you can use SMCONVRT to convert a set of
physical volumes into a set of one disk pools.
There are several disadvantages to using one disk pools:

Each pool requires a pool process and one or more virtual disk processes. If a
large number of disks are involved, the extra memory and other resources used by
those pool processes can cause performance to degrade.

The option of relocating a file to another disk in the pool for purposes of load
balancing does not exist in a one disk pool.

If it becomes necessary to expand the amount of storage in the pools by adding
more disks, an extra disk per pool is required, doubling the total number of disks.
With larger pools, the amount of storage can be increased in smaller percentage
increments.
For details on pool consolidation, see Pool Consolidation on page 6-1.