Vivotek NR9682-v2 64-Channel NVR (No HDD) - Manual (Page 55)

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User's Manual - 55
RAID 50
A RAID50 drive group provides the features of both RAID0 and RAID5 drive groups. A RAID50
drive group includes both distributed parity and drive striping across multiple drive groups. A
RAID50 drive group is best implemented on two RAID5 drive groups with data striped across
both drive groups.
A RAID50 drive group breaks up data into smaller blocks and then stripes the blocks of data to
each RAID5 disk set. A RAID5 drive group breaks up data into smaller blocks, calculates parity
by performing an exclusive OR operation on the blocks, and then performs write operations
to the blocks of data and parity to each drive in the drive group. The size of each block is
determined by the stripe size parameter, which is set during the creation of the RAID set.
A RAID level 50 drive group can support up to eight spans and tolerate up to eight drive failures,
though less than total drive capacity is available. Though multiple drive failures can be tolerated,
only one drive failure can be tolerated in each RAID 5 level drive group.
The following table provides an overview of a RAID50 drive group.
Uses Appropriate when used with data that requires high reliability, high request rates, high
data transfer, and medium-to-large capacity.
Also used when a virtual drive of greater than 32 drives is needed.
Strong points Provides high data throughput, data redundancy, and very good performance.
Weak points Requires two times to eight times as many parity drives as a RAID 5 drive group.
Drives Eight spans of RAID 5 drive groups that contain 3 to 32 drives each (limited by the
maximum number of devices supported by the controller)