The rebuild of a broken drive is the process of reconstructing a RAID Array (except on a RAID 0) to be consistent in case a hard disk drive has a failure like SMART Errors or mechanically issue (for example, klick of death)
Reasons for are broken disk :
- Bad Blocks
- SMART Errors
- Multiple Command Time Outs
Such Reasons are reported in Webinterface from WebPAMProe:
Once a RAID rebuild starts on a replaced disk, data (on block level, not file system level) will be integrated with parity data & RAID algorithm.
When a physical drive is indicated as dead or reports other errors, then it should be replaced ASAP.
Once the physical drive is replaced with a new hard Drive the Array (Note: State is Degraded) that contains that drive needs to be rebuilt.
If you are not using Auto Rebuild (which requires a Spare Drive) then you must rebuild, the disk manually after the affected drive has been replaced.
Follow the instructions here to rebuild an array on the Vess A-Series: