User guide

Compaq Smart Array 431 Controller User Guide
■ Compaq Insight Manager can be used to detect failed drives remotely
across a network.
Problems such as reduced system performance or disk errors reported by the
operating system do not necessarily imply that a drive has or has not been
failed. If drive failures or repeated errors are suspected, Compaq recommends
that Array Diagnostics Utility (ADU) be run on the system.
In the event of a drive failure, the condition of the logical drive will vary
depending upon the fault-tolerance method used. Since a single array of
physical drives can contain multiple logical drives with different fault
tolerance methods, conditions of each logical drive on the same array are not
necessarily the same. At any one time, if more drives are failed than the fault
tolerance mode allows, fault tolerance is referred to as being “compromised”
and the condition of the logical drive can be referred to as “failed.” If a logical
volume is “failed,” all requests from the operating system will be rejected with
“unrecoverable” errors.
Non-fault-tolerant Logical Drives cannot sustain drive failures. If any physical
drive in the array is failed, the condition of all non-fault tolerant logical drives
in the same array will also be “failed.” This is because data is striped across all
drives in the array.
RAID 1 Logical Drives
■ can sustain multiple drive failures as long as failed drives are not
mirrored to one another.
■ will be in a “failed” condition if any two failed drives are mirrored to
one another.
■ will be in a “regenerating” condition if at least one drive is failed, and
no failed drives are mirrored to one another.
■ will be in a “rebuilding” condition if a previously failed drive has been
replaced and the replacement drive is rebuilding. The volume may also
be in a “rebuilding” condition following a drive failure if a spare drive
was previously assigned and is rebuilding.