Administrator Guide

• You can use only unassigned physical disks with Optimal status as hot spare physical disks.
• You can unassign only hot spare physical disks with Optimal, or Standby status. You cannot unassign a hot spare physical disk that
has the In Use status. A hot spare physical disk has the In Use status when it is in the process of taking over for a failed physical disk.
• Hot spare physical disks must be of the same media type and interface type as the physical disks that they are protecting.
• If there are secure disk groups and security capable disk groups in the storage array, the hot spare physical disk must match the
security capability of the disk group.
• Hot spare physical disks must have capacities equal to or larger than the used capacity on the physical disks that they are protecting.
• The availability of enclosure loss protection for a disk group depends on the location of the physical disks that comprise the disk group.
To make sure that enclosure loss protection is not affected, you must replace a failed physical disk to initiate the copyback process.
See Enclosure Loss Protection.
To assign or unassign hot spare physical disks:
1. In the AMW, select the Hardware tab.
2. Select one or more unassigned physical disks.
3. Perform one of these actions:
• From the menu bar, select Hardware > Hot Spare Coverage.
• Right-click the physical disk, and select Hot Spare Coverage from the pop-up menu.
The Hot Spare Physical Disk Options window is displayed.
4. Select the appropriate option, you can select:
• View/change current hot spare coverage—to review hot spare coverage and to assign or unassign hot spare physical disks, if
necessary. See step 5.
• Automatically assign physical disks—to create hot spare physical disks automatically for the best hot spare coverage using
available physical disks.
• Manually assign individual physical disks—to create hot spare physical disks out of the selected physical disks on the
Hardware tab.
• Manually unassign individual physical disks—to unassign the selected hot spare physical disks on the Hardware tab. See
step 12.
NOTE: This option is available only if you select a hot spare physical disk that is already assigned.
5. To assign hot spares, in the Hot Spare Coverage window, select a disk group in the Hot spare coverage area.
6. Review the information about the hot spare coverage in the Details area.
7. Click Assign.
The Assign Hot Spare window is displayed.
8. Select the relevant Physical disks in the Unassigned physical disks area, as hot spares for the selected disk and click OK.
9. To unassign hot spares, in the Hot Spare Coverage window, select physical disks in the Hot spare physical disks area.
10. Review the information about the hot spare coverage in the Details area.
11. Click Unassign.
A message prompts you to confirm the operation.
12. Type yes and click OK.
Hot spares and rebuild
A valuable strategy to protect data is to assign available physical disks in the storage array as hot spares. A hot spare adds another level of
fault tolerance to the storage array.
A hot spare is an idle, powered-on, stand-by physical disk ready for immediate use in case of disk failure. If a hot spare is defined in an
enclosure in which a redundant virtual disk experiences a physical disk failure, a rebuild of the degraded virtual disk is automatically initiated
by the RAID controller modules. If no hot spares are defined, the rebuild process is initiated by the RAID controller modules when a
replacement physical disk is inserted into the storage array.
Global hot spares
The MD Series storage arrays support global hot spares. A global hot spare can replace a failed physical disk in any virtual disk with a
redundant RAID level as long as the capacity of the hot spare is equal to or larger than the size of the configured capacity on the physical
disk it replaces, including its metadata.
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Disk groups, standard virtual disks, and thin virtual disks