Users Guide

Rebuilding Redundant Information
Does my controller support this feature? See Supported Features.
If you have a redundant virtual disk, you can reconstruct the contents of a failed physical disk onto a new
disk or a hot spare. A rebuild can take place during normal operation, but it degrades performance.
Related Concepts
Replacing A Failed Disk
Setting The Rebuild Rate
A Rebuild Does Not Work
Managing Virtual Disk Bad Block Management
Virtual disk bad blocks are bad blocks on one or more member physical disks. The read operation on the
virtual disks having bad blocks may fail.
Storage Management generates a critical alert (2387) to notify you of the bad blocks on the virtual disk.
Virtual disk bad blocks are discovered when the controller performs any operation that requires scanning
the disk. Examples of operations that may result in this alert are:
• Consistency check
• Rebuild
• Virtual disk format
• I/O
• Patrol Read
Recovering a physical disk bad block depends on the RAID level and state of the virtual disk. If a virtual
disk is redundant, the controller can recover a bad block on a physical disk. If a virtual disk is not
redundant, then the physical disk bad block results in a virtual disk bad block.
The following table describes some of the possible scenarios that may/may not result in virtual disk bad
blocks:
Table 29. Sample Scenarios For Virtual Disk Bad Blocks
RAID Level Virtual Disk State Scenario Result
RAID 0 Degraded One bad block on a
physical disk.
The controller cannot
regenerate data from
the peer disks as there is
no redundancy. This
results in a virtual disk
bad block.
RAID 5 Ready One bad block on a
physical disk.
The controller
regenerates data from
the peer disks and sends
a Write to the bad block.
The disk then remaps
the Logical Block
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