20
Chapter 1: Features of the CHALLENGE RAID Storage System
RAID Hot Spare
A hot spare is a dedicated replacement disk unit on which users cannot store
information. The capacity of a disk module that you bind as a hot spare must
be at least as great as the capacity of the largest disk module it might replace.
Note:
The hot spare is not available for RAID-0, because this RAID level
does not provide data redundancy.
If any disk in a RAID-5 group, RAID-1 mirrored pair, or RAID-1_0 group
fails, the SP automatically begins rebuilding the failed disk module’s
structure on the hot spare. When the SP finishes rebuilding, the disk group
functions as usual, using the hot spare instead of the failed disk. When you
replace the failed disk, the SP starts copying the data from the former hot
spare onto the replacement disk. When the copy is done, the disk group
consists of disk modules in the original slots, and the SP automatically frees
the hot spare to serve as a hot spare again.
Note:
The SP finishes rebuilding the disk module before it begins copying
data, even if you replace the failed disk during the rebuild process.
A hot spare is most useful when you need the highest data availability. It
eliminates the time and effort needed for someone to notice that a module
has failed, find a suitable replacement module, and insert it.
You can have one or more hot spares per storage system. Any module in the
storage system can be configured as a hot spare except for modules A0, B0,
C0, D0, E0, and A3, because they may store the licensed internal code or
serve as the storage system’s cache vault.
For example, assume that the modules in slots A0-E0 are a RAID-5 group,
those in slots A1 and B1 are a RAID-1 mirrored pair, and the module in A2
is a hot spare, as shown in Figure 1-13. If module D0 fails, the SP
immediately begins rebuilding the RAID-5 group using the hot spare. When
it finishes, the RAID-5 group consists of disk modules A0, B0, C0, A2, and
E0.
Содержание CHALLENGE RAID
Страница 1: ...CHALLENGE RAID Owner s Guide Document Number 007 2532 004 ...
Страница 6: ......
Страница 10: ......
Страница 17: ...3 Figure 1 2 CHALLENGE RAID Rack ...
Страница 48: ......
Страница 62: ......
Страница 72: ......
Страница 92: ......
Страница 106: ......
Страница 110: ......
Страница 141: ......