Product manual

Chapter 8: Troubleshooting
395
RAID Controller Problems
RAID controller problems include:
• Maintenance Mode (page 395)
• Finding and Correcting the Cause of the Problem (page 395)
• Taking a RAID Controller out of Maintenance Mode (page 396)
• Unsaved Data in the Controller Cache (page 398)
Controller problems occur when one of the controllers goes into maintenance
mode.
Maintenance Mode
For VTraks with two RAID controllers, one of them enters maintenance mode in
the event of:
• A difference of some kind between the two controllers (described below)
• An internal controller failure
When a controller enters maintenance mode, it goes offline and it displays N/A
(not accessible) under Readiness Status.
You must find and correct the cause of the problem and then take the controller
out of maintenance mode (see page 396).
Finding and Correcting the Cause of the Problem
External Checks
Make the following external checks to your VTrak subsystem. Be sure that:
• Both RAID controllers are present, fully inserted into their slots, and locked
into place.
• The RAID controllers match, meaning both are Fibre Channel or both are
iSCSI.
• All SAS expansion cables from the RAID controllers to external JBOD units
in good condition and are securely connected.
Important
A disconnected SAS expansion cable causes the two RAID
controllers to see a different set of configured drives. This
condition is the most common cause of a controller entering
maintenance mode.