USB3.0/eSATA/1394b-to-SATA II RAID Subsystem
Quick Setup Guide
13
On-line Auto Rebuild
When the RAID controller enters degraded mode, it will search possible spare drive to do
RAID rebuild automatically with the following searching priority:
1.
Search the original RAID drive related hard disk.
2.
Search the previously reserved spare hard disk.
3.
In auto mode, if there is a stand-by hard disk which is not a member of an
existing RAID, the RAID controller will use it.
The RAID controller will automatically rebuild the system when no host controller
commands are executed. The firmware or application is able to specify
1.
The time interval between two rebuild actions, or
2.
When the RAID controller will start rebuild after host controller is idle.
Up-to-date rebuild status will be recorded in RAID hard disks. When rebuild process is
terminated for some reason, the RAID controller will resume the rebuild from the same
place where it is interrupted last time. There is no need to rebuild from the beginning.
On-line Command Based Bad Sector Recovery
Hard disk might be defective in some sectors. When the defect causes write operation
error in system, O.S. (e.g. Windows or Linux) will do some error handling to prevent
users from using these defective sectors. However, when there are problems in reading
operation, some important data might be lost.
The RAID controller supports command based bad sector recovery mechanism to secure
read operation in RAID 1/3/5/10 modes. If read error occur, the RAID controller marks
this hard disk status “non-readable”. While host controller tries to read the defective
region again, the RAID controller will read it just like in degrade mode. That is, data in
the “non-readable” hard disk is recovered by some special algorithm.
Only RAID 10 mode allows more than one defective hard disks. After the RAID controller
starts command based bad sector recovery algorithm, firmware or application will inform
users the status so that user could decide whether to replace the defective hard disk
right away.
