IBM ServeRAID, User Reference

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Drive-state descriptions
This section provides descriptions of the physical and logical drive states.
ServeRAID publications frequently refer to these states.
Physical-drive-state descriptions
The following table provides descriptions of the valid physical drive states.
Drive state Meaning
Defunct A physical drive in the online, hot-spare, or rebuild state has become defunct. It does not
respond to commands, which means that the ServeRAID controller cannot communicate
properly with the drive.
If a physical drive has become defunct, see “Rebuilding a defunct drive” on page 157.
Hot spare A hot-spare drive is a physical drive that is defined for automatic use when a similar drive
fails.
Online The drive is online. It is functioning properly and is part of an array.
Rebuilding The drive is being rebuilt.
For more information on rebuilding a drive, see “Rebuilding a defunct drive” on page 157.
Ready The ServeRAID controller recognizes a ready drive as being available for definition.
Standby hot spare A standby hot spare is a hot-spare drive that the ServeRAID controller has spun down. If an
online drive becomes defunct and no suitable hot-spare drive is available, a standby
hot-spare drive of the appropriate size automatically spins up and enters the rebuild state.
Logical-drive-state descriptions
The following table provides descriptions of the valid logical drive states.
Drive state Meaning
Blocked The blocked state is reserved for RAID level-0 logical drives that are part of the same array
as one or more of the following:
v A RAID level-1 logical drive
v
A RAID level-1E logical drive
v A RAID level-5 logical drive
If a physical drive in such an array fails, the RAID level-0 logical drives enter the offline state,
while the other logical drives enter the critical state.
After you replace the failed physical drive, a rebuild operation starts and reconstructs the data
stored in any RAID level-1, level-1E, or level-5 logical drives; at the same time, the RAID
level-0 logical drives enter the blocked state. RAID level-0 logical drives cannot be rebuilt,
since they do not contain redundant data.
After the rebuild operation is completed, you can unblock the RAID level-0 logical drives and
access them once again. However, the logical drive might contain damaged data. You must
re-create, reinstall, or restore the data from the most recent backup disk or tape to the RAID
level-0 logical drive.
Critical migrating A logical drive in the critical state that is undergoing a logical-drive migration (LDM).
Critical system The ServeRAID controller uses this reserved state during a logical-drive migration when the
logical drive is in the critical state.
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IBM ServeRAID: User’s Reference, Version 5.10