QNAP TS-859 Pro+, User Manual, Page: 51 / 242

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Single Disk Volume
Each hard disk drive is used as a
standalone disk. If a disk is damaged,
all the data will be lost.
JBOD (Just a bunch of disks)
JBOD is a collection of hard disk drives
that does not offer any RAID protection.
The data are written to the physical
disks sequentially. The total storage
capacity equals to the sum of the
capacity of all the member drives.
RAID 0 Striping Disk Volume
RAID 0 (striping disk) combines 2 or
more hard disk drives into one larger
volume. The data is written to the hard
disk drives without any parity
information and no redundancy is
offered. The disk capacity equals the
number of hard disk drives in the array
times the size of the smallest hard drive.
RAID 1 Mirroring Disk Volume
RAID 1 duplicates the data between two
hard disk drives to provide disk
mirroring. To create a RAID 1 array, a
minimum of 2 hard drives are required.
RAID 5 Disk Volume
The data are striped across all the
drives in a RAID 5 array. The parity
information is distributed and stored
across each drive. If a member drive
fails, the array enters degraded mode.
After installing a new drive to replace
the failed one, the data can be rebuilt
from other member drives that contain
the parity information.