User's Manual
In this case, you can unassign the global hot spare after creating a new virtual disk and then assign a new and larger hot spare to cover all redundant virtual
disks on the controller. See "RAID Controller Technology: SAS" to determine whether the controller is using SAS technology.
Dedicated Hot Spare Considerations
The following considerations apply to dedicated hot spares:
l Considerations for RAID 10 and RAID 50. If you have created a RAID 10 or RAID 50 virtual disk that does not fully consume its member physical disks,
then you will not be able to assign a dedicated hot spare to the RAID 10 or RAID 50 virtual disk. Storage Management does not allow you to create RAID
10 and RAID 50 virtual disks from partial physical disks. You will therefore not encounter this situation if you are using Storage Management to create
your virtual disks. If, however, the RAID 10 or 50 virtual disk was created using another application and if it does contain partial physical disks, then you
will not be able to assign a dedicated hot spare to the virtual disk.
l Considerations for Multiple Dedicated Hot Spares. Storage Management does not allow you to assign more than one dedicated hot spare to a virtual
disk. On some controllers, you can use the BIOS to assign more than one dedicated hot spare. In this case, Storage Management recognizes the hot
spares assigned in the BIOS but does not allow you to assign additional dedicated hot spares.
Global Hot Spare Considerations on a SAS 6/iR
The SAS 6/iR controller enables you to assign two global hot spares. The controller firmware remembers the hot spare assignment even after the physical
disks that you assigned as hot spares have been removed. In other words, in the case of a disk removal, the firmware may assume that a hot spare is
present when it is not. In this case, the firmware may prevent you from assigning a new global hot spare as the firmware assumes that a global hot spare is
already assigned.
When a physical disk fails in a redundant virtual disk, the failed disk is rebuilt onto the hot spare. In this case, the controller firmware reassigns the slot
containing the failed disk as the hot spare. In this circumstance, a disk not previously assigned as a global hot spare becomes a hot spare through failure or
removal.
To ensure that the controller firmware always has a healthy physical disk as a global hot spare, do the following:
l When removing a physical disk that is assigned as a global hot spare, unassign the hot spare before removal and reassign another physical disk as the
global hot spare.
l Immediately replace any physical disk that has failed or been removed. This ensures that a healthy disk resides in a slot that the controller firmware
assumes is a hot spare.
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