ICP RS Series User Manual page 181

181
The error state
RAID 4/5
If a second hard disk should fail while the Array Drive is in the fail or rebuild state, it is not
possible to continue the working session without restrictions. The disk array is still avail-
able for I/Os, but data loss and error messages on the host level are possible.
Usually you have to remove the Array Drive and build a new one. In some situations (see
below) there might be still a chance to reset the array. Please contact our support depart-
ments.
To find out why the drives failed, the last status from the Physical Drive information is very
helpful. Additionally you should check for retries and / or reassigns.
A drive failure may also be the result of bad or cabling, wrong termination or overheating.
Some of these states may become the addendum patch (e.g. build/patch, ready/patch).
This word indicates that the original Array Drive went through a significant procedure. I.e.,
the parity information was recalculated anew. Or, the Array Drive has been patched from
the error state into the fail state. This may become extremely helpful in a situation where
two Logical Drives of an Array Drive, fail at the same time, but only one of the two Logical
Drives is really defective and the other was blocked out, since it was connected with the
same I/O channel as the defective one. The Array Drive's state is error and normally all data
would be lost. The ICP Controllers include some functions, which allow the patch of this
Array Drive from the error state into the fail sate. Before the actual patch, the defective drive
has to be physically removed from the Array Drive. Such a patch-procedure is a real sheet-
anchor and should only be used, after a detailed consultation with a trained support per-
son (a printout of the Save Information file, is extremely helpful).