Filter
Top Products
ADAC Ultra2 S466 Hardware Guide
12
Parity
Parity generates a set of redundancy data from two or more
parent data sets. The redundancy data can be used to
reconstruct one of the parent data sets. Parity data does not
fully duplicate the parent data sets. In RAID, this method is
applied to entire drives or stripes across all disk drives in
an array. The types of parity are:
Type Description
Dedicated Parity The parity of the data on two or more disk drives is
stored on an additional disk.
Distributed
Parity
The parity data is distributed across all drives in the
system.
If a single disk drive fails, it can be rebuilt from the parity
and the data on the remaining drives.
RAID level 3 combines dedicated parity with disk striping.
The parity disk in RAID 3 is the last logical drive in a
RAID set.
RAID level 5 combines distributed parity with disk
striping. Parity provides redundancy for one drive failure
without duplicating the contents of entire disk drives, but
parity generation can slow the write process. A dedicated
parity scheme during normal read/write operations is
shown below: