Dell PowerEdge RAID Controller H700 - Manual (Page 141)

Troubleshooting 141
Degraded State of Virtual Disks
A redundant virtual disk is in a degraded state when one or more physical disks
have failed or are inaccessible. For example, if a RAID 1 virtual disk consists
of two physical disks and one of them fails or become inaccessible, the virtual
disk become degraded.
To recover a virtual disk from a degraded state, you must replace the failed
physical disk and rebuild it. Once the rebuilding process is complete, the
virtual disk state changes from degraded to optimal. For information on
rebuilding the disk, see "Performing a Manual Rebuild of an Individual
Physical Disk" on page 111.
Memory Errors
Memory errors can corrupt cached data, so the controllers are designed to
detect and attempt to recover from the memory errors. Single-bit memory
errors can be handled by the controller and do not disrupt normal operation.
A notification is sent if the number of single-bit errors exceeds a threshold
value.
Multi-bit errors are more serious as they result in corrupted data and data
loss. The following are the actions that occur in the case of multi-bit errors:
• If a multi-bit error occurs while accessing data in the cache when the
controller is started with dirty cache, the controller discards the cache
contents. The controller generates a warning message to the system
console to indicate that the cache was discarded and generates an event.
• If a multi-bit error occurs at run-time either in code/data or in the cache,
the controller stops.
• The controller logs an event to the controller’s internal event log and
a message during POST is displayed indicating a multi-bit error
has occurred.
NOTE: In case of a multi-bit error, contact Dell Technical Support.
PERC7.2_UG.book Page 141 Thursday, March 3, 2011 2:14 PM