Mylex DAC960PG, Installation Manual

Page: 42 / 106

Drive Management
2-18 DAC960PG Installation Guide
Drive Management
The DAC960PG functions that monitor and control the operation of the
physical drives and logical units are instrumental to the controller’s ability to
perform RAID management and automated error recovery tasks.
Controlling Physical Drive States
The state of a physical drive refers to a SCSI drive's current operational
status. At any given time, a SCSI drive can be in one of several states: ON-
LINE, STANDBY, READY, DEAD, REBUILD, or WRITE-ONLY.
The controller stores the state of the attached SCSI drives in its non-volatile
memory. This information is retained even after power-off. If a SCSI disk is
labeled DEAD in one session, it will stay in the dead state until a change is
made either by using a system level utility or after a maintenance/rebuild
procedure is performed.
On-line (ONL)
A SCSI drive (physical drive) is on-line if it:
1. Is powered on
2. Has been defined as a member of a drive group
3. Is operating properly.
Standby (SBY)
A SCSI disk drive is in a standby state if it:
1. Is powered on
2. Is able to operate properly
3. Has not been defined as part of any drive group.
4. Has been defined as a standby
Dead (DED)
A drive is dead if it was previously configured, but:
1. Is not present
2. Is present, but not powered on
3. Failed to operate properly and was killed by the controller