Avago Technologies 3ware SAS 9750-16i4e - Manual (Page 224)

Chapter 11. 3DM2 Reference
212 3ware SATA+SAS RAID Controller Card Software User Guide, Version 10.2
can select the drive you want to use. If the degraded unit has more than one
failed drive (for example, a RAID 10 where both mirrored pairs each have a
failed drive), you will repeat this process a second time.
If rebuild scheduling is enabled on the Scheduling page, the unit will not start
actively rebuilding until the scheduled time, and the status will change to say
“Rebuild-Paused.” (The Unit Details page indicates whether a unit is actively
rebuilding.) If rebuild scheduling is not enabled, the rebuild process will
begin right away.
For more information about rebuilds, see “To verify a unit through 3BM” on
page 153.
Migrate Unit. Reconfigures a unit while it is on-line. Migration can be used to
change the RAID level, to expand the capacity by adding additional drives, or
to change the stripe size.
When you select a unit and click Migrate Unit , a dialog box appears which
lists the drives in the unit and any additional available drives. In the dialog
box are two drop-down menus, one for choosing the RAID level and one for
choosing stripe size.
Figure 104. Migrating a unit
You can only migrate a unit to a RAID level that will be equal to or larger than
the original unit. For example, you can migrate from a RAID 5 array with 4
drives to a RAID 0 with four drives but you cannot migrate from a RAID 5
with four drives to a RAID 10 with four drives.
After you have specified changes to the unit, the Unit Maintenance screen
reflects your changes and shows the percentage of migration completed.
While the unit is migrating, you can still access the unit as normal but the
performance will be lower. You can adjust the I/O rate with the radio buttons
on the Controller Settings page. (See “Setting Background Task Rate” on
page 162.)
Warning: Once migration of a unit is started, it can be paused, but it can not be
cancelled.