Avago Technologies 3ware 9650SE-12ML (Channel) - Manual (Page 286)

Troubleshooting
274 3ware SAS/SATA RAID Software User Guide, Version 9.5.1
0022 Upgrade UDMA mode
Event Type
Warning
Cause
During a self-test, the controller found that a drive was not in the optimal
UDMA mode and upgraded its UDMA transfer rate.
Action
None required. The drive and cable are working in optimal mode.
0023 Sector repair completed
Event Type
Warning
Cause
The 3ware RAID controller moved data from a bad sector on the drive to a
new location.
Background Information
The 3ware RAID controller supports a feature called dynamic sector repair
that allows the unit to recover from certain drive errors that would normally
result in a degraded unit situation. For redundant units such as RAID 1, 5, 6,
10, and 50, the 3ware RAID controller essentially has two copies of your data
available. If a read command to a sector on a disk drive results in an error, it
reverts to the redundant copy in order to satisfy the host’s request. At this
point, the 3ware RAID controller has a good copy of the requested data in its
cache memory. It will then use this data to force the failing drive to reallocate
the bad sector, which essentially repairs the sector.
Action
Sector repairs are an indication of the presence of grown defects on a
particular drive. While typical modern disk drives are designed to allow
several hundred grown defects, special attention should be paid to any drive in
a unit that begins to indicate sector repair messages. This may be an indication
of a drive that is beginning to fail. You may wish to replace the drive,
especially if the number of sector repair errors exceeds 3 per month.