DATOptic RM12-S6.TB - Rackmount - Manual (Page 79)

APPENDIX
188
tomatically assigned as a hot spare if any hot spare disk was
used to rebuild and without new installed drive replaced it. In
this condition, the Auto Declare Hot-Spare status will be disap-
peared if the RAID subsystem has since powered off/on.
The Hot-Swap function can be used to rebuild disk drives in
arrays with data redundancy such as RAID level 1, 1E, 3, 5, 6,
10, 30, 50 and 60.
• Auto Rebuilding
If a hot spare is available, the rebuild starts automatically when
a drive fails. The RAID controllers automatically and transpar-
ently rebuild failed drives in the background at user-definable
rebuild rates.
If a hot spare is not available, the failed disk drive must be re-
placed with a new disk drive so that the data on the failed drive
can be automatically rebuilt and so that fault tolerance can be
maintained.
RAID controllers will automatically restart the system and
rebuilding process if the system is shut down or powered off
abnormally during a reconstruction procedure condition.
When a disk is hot swapped, although the system is functionally
operational, the system may no longer be fault tolerant. Fault
tolerance will be lost until the removed drive is replaced and the
rebuild operation is completed.
During the automatic rebuild process, system activity will con-
tinue as normal, however, the system performance and fault
tolerance will be affected.
• Adjustable Rebuild Priority
Rebuilding a degraded volume incurs a load on the RAID sub-
system. The RAID controllers allow the user to select the re-
build priority to balance volume access and rebuild tasks appro-
priately. The Background Task Priority is a relative indication of
how much time the controller devotes to a background opera-