Hardware Installation
PixelStor 5000 User Manual
Rev. 1, May 2013
5-84
5.2.5
SAS Cable Disconnect (Lost Connection to Expansion Enclosure)
If a cable fails or is accidentally disconnected, the system will react as if the SAS IO Module
failed. (See 5.2.4
“SAS IO Expander Failure” in previous section)
Corrective action:
Dual Controller - the system will fail over and the controller with healthy a SAS IO
connections will take over all the disks without disruption to data access. The
administrator can reconnect the SAS cable and the system will automatically fail-back to
regain redundancy.
Single Controller - all connected expansion enclosures (and drives) will become
unavailable. The administrator will need to reconnect the SAS cable and do a Disk
Group Restore to reactivate all the disk groups brought off line by the failure.
5.2.6
Drive Failure
If a one drive fails in a RAID 1/5/10 DG, or two drives in a RAID 6 DG, the DG will go into
degraded mode. If a global spare is present in the system, the spare will be automatically be
added to the DG and a rebuild of the DG will be initiated. (Note: RAID 0 by definition has no
protection and therefore cannot be rebuilt.)
Corrective action:
No Spare
– Replace the failed drive and the system will automatically start a rebuild of
the DG. (It is recommended that a global spare is always installed in the system to
insure data availability.
Spare Present - Replace failed drive. This will automatically be added to the system as a
global spare.
5.2.7
Unhealthy RAID Disk Group
If a RAID Group experiences a drive fault that is unrecoverable, the System Health Alert is
triggered. For example, this can happen if a RAID 0 Disk Group experiences a drive failure or a
RAID 5 Disk Group experiences two consecutive drive failures.
Corrective action:
Recover the Disk Group from a recent back-up.