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Chapter 1: Features of the CHALLENGE RAID Storage System
RAID Levels
The CHALLENGE RAID system supports these levels of RAID:
•
RAID-0 group: nonredundant array
•
RAID-1: mirrored pair
•
RAID-1_0 group: mirrored RAID-0 group
•
RAID-5 group: individual access array
Caution:
Use only CHALLENGE RAID disk modules to replace failed disk
modules. CHALLENGE RAID disk modules contain proprietary firmware
that the storage system requires for correct functioning. Using any other
disks, including those from other Silicon Graphics systems, can cause failure
of the storage system. Swapping disk modules within a CHALLENGE RAID
storage system is also not recommended, particularly disk modules in slots
A0, B0, C0, and A3, which contain the licensed internal code, and those in
slots D0 and E0, which serve with A0, B0, and C0 as the storage system cache
vault.
RAID-0 Group: Nonredundant Array
Three to sixteen disk modules can be bound as a RAID-0 group. A RAID-0
group uses striping; see “Enhanced Performance: Disk Striping,” earlier in
this chapter. You might choose a RAID-0 group configuration when fast
access is more important than high availability. On IRIX 5.3 with XFS you
can software-mirror the RAID-0 group to provide high availability.
Caution:
The hardware does not maintain parity information on any disk
module for RAID-0 the way it does for other RAID levels. Failure of a disk
module in this RAID level results in loss of data.