PLANET NAS-7400 User Manual
118
7.3 Spare Drive
A spare is a disk drive that has been designated to replace a failed disk drive
in a RAID Volume. In the event of the failure of a disk drive within a RAID 1
or three-drive RAID 5 Volume, the spare drive is activated as a member of
the RAID Volume to replace a disk drive that has failed.
A spare drive cannot replace the failed drive in a RAID 0 Volume because of
the way in which data is written to the disk drives under RAID 0.
A spare drive is not available for a RAID 10 Volume because RAID 10
requires all four disk drives in the NAS-7400 enclosure. However, when you
replace the failed disk drive, the NAS-7400 will automatically rebuild the
RAID Volume using the new disk drive.
You must designate a disk drive as a Spare. By default, and unassigned disk
drive is Free. Use PASM to designate the Free disk drive as a Spare.
7.4 Automatic Rebuilding
When a disk drive in your RAID 1, 5, or 10 Volume fails, and a replacement
disk drive become available, the RAID Volume will rebuild itself to the new
disk drive automatically.
For RAID 1 and three-drive RAID 5 Volumes, you can designate a spare drive.
If a spare drive is present when the RAID Volume experiences a disk drive
failure, the rebuild will start automatically using the spare drive.
For RAID 1, RAID 5, and RAID 10 Volumes without a spare drive, the RAID
Volume will begin to rebuild itself automatically when you remove the failed
disk drive and install a new disk drive.
A RAID 0 Volume cannot be rebuilt because of the way in which data is
written to the disk drives under RAID 0. Even if there is a designated spare
drive, rebuilding is not possible for RAID 0 Volumes.
7.5 Partition and Format
When you create a RAID Volume on NAS-7400, the RAID Volume is
automatically partitioned and formatted for you.
To use your RAID Volume, you must create Folders on the RAID Volume and