Mylex DAC960PG, Installation Manual

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Glossary
Manual No. 771971 Glossary-7
Ready: A SCSI disk drive is in a “ready” state if it...
Is powered on; and
Is available to be configured during the current session but remains
unconfigured.
Online: A SCSI disk drive is in an “online” state if it...
Is powered on; and
Has been defined as a member of a drive group; and
Is operating properly.
Standby: A SCSI disk drive is in a “standby” state if it...
Is powered on; and
Is able to operate properly; and
Was NOT defined as part of any drive group.
Dead: A SCSI disk drive is in a “dead” state if it...
Is not present; or
If it is present but not powered on; or
If it failed to operate properly and was ‘killed’ by the controller.
When the controller detects a failure on a disk, it “kills” that disk by
changing its state to “dead.” A SCSI drive in a dead state does not participate
in any I/O activity. No commands are issued to dead drives.
Rebuild: A SCSI disk drive is in a “rebuild” state...
While it is in the process of being rebuilt. During this process, data is
regenerated and written to the disk drive. This state is also referred to as
‘Write-Only’ (WRO).
Segment Size
The Segment Size function is set in conjunction with stripe size and
represents the size of the data “chunk” that will be read or written at one
time. Under DACCF, the segment size (also known as “cache line size”)
should be based on the stripe size you selected. The default segment size for
Mylex DAC960PG controllers is 8K.