Installation guide

G-4 DAC960PG/PJ Installation Guide
Critical: A Logical Drive is in a “critical” state if...
It has been configured at RAID level 1, 3, 5, or 0+1; and
One (and only one) of its SCSI drives is not “online.”
A logical drive is considered “critical” because any failure of another of its
SCSI drives may result in a loss of data.
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Note
I/O operation can only be performed with system
drives that are online or critical.
Offline: A Logical Drive is in an “offline” state if...
No data can be read from it or written to it.
System commands issued to offline logical drives are returned with an error
status: no operations can be performed on offline logical drives. A logical
drive can be “offline” under one of two situations described below:
• It is configured with a redundant RAID level (1, 3, 5, or 0+1), and two
or more of its SCSI drives are not “online”; or
• It is configured at RAID level 0, JBOD, or in a spanned set, and one or
more of its SCSI drives are not “online.”
Logical Drives
See “System Drives.”
Mirroring
Refers to the 100 percent duplication of data on one disk drive to another
disk drive. Each disk will be the mirror image of the other.
Pack
See “Drive Groups (or Drive Packs).”
Parity
See “Rotated XOR Redundancy.”