Dell PowerEdge RAID Controller H700 - Manual (Page 34)

34 Storage Controller Features
• Battery and optional Non-Volatile Cache backup of controller cache to
protect data
• Detection of batteries with low charge after boot up
The next sections describe some methods to achieve fault tolerance.
Using Persistent Hot Spare Slots
The H700 and H800 cards can be configured so that system backplane or
storage enclosure disk slots are dedicated as hot spare slots. This feature can
be enabled using the Dell OpenManage storage management application.
Once enabled, any slots with hot spares configured automatically become
persistent hot spare slots. If a hot spare disk fails or is removed, a replacement
disk that is inserted into the same slot automatically becomes a hot spare with
the same properties as the one it is replacing. If the replacement disk does not
match the disk protocol and technology, it does not become a hot spare.
NOTE: Any hot spares assigned to an encrypted Virtual Disk must also be capable
of encryption (SED).
Physical Disk Hot Swapping
Hot swapping is the manual replacement of a disk while the H700 and H800
cards are online and performing their normal functions.
The following requirements must be met before hot swapping a physical disk:
• The system backplane or enclosure must support hot swapping for the
PERC H700 and H800 cards to support hot swapping.
• The replacement disk must be of the same protocol and disk technology.
For example, only a SAS hard drive can replace a SAS hard drive; only a
SATA SSD can replace a SATA SSD.
• The replacement disk must be of equal or greater capacity than the one
it is replacing.
Failed Physical Disk Detection
Failed physical disks are detected and rebuilds automatically start to new
disks that are inserted into the same slot. Automatic rebuilds can also happen
transparently with hot spares. If you have configured hot spares, the
controllers automatically try to use them to rebuild failed physical disks.
PERC7.2_UG.book Page 34 Thursday, March 3, 2011 2:14 PM