HP Workstations RAID Primer

RAID
Level
Typical RAID Layout Description Advantages Disadvantages
RAID 0
D1[1] D1[2] D1[3]
D2[1] D2[2] D2[3]
D3[1] D3[2] D3[3]
D4[1] D4[2] D4[3]
A three drive RAID 0
configuration
Striped Disk Array – 2 or
more physical drives
Typically higher
performance
Lack of redundancy
implies that a single
disk failure is
unrecoverable
RAID 1
D1 D1
D2 D2
D3 D3
D4 D4
A two drive RAID 1
configuration
Mirrored Disk Array – 2
physical drives
More fault tolerant
than RAID 0
Typically slower
performance; half the
physical disk space is
used
RAID 5
D1[1] D1[2] D1[3] P1
D2[1] D2[2] P2 D2[3]
D3[1] P3 D3[2] D3[3]
P4 D4[1] D4[2] D4[3]
A four drive RAID 5
configuration
Striped Disk Array with
Parity – 3 or more
physical drives
Parity is employed to
ensure data integrity
Often difficult to
rebuild in case of a
disk failure
RAID 10
D1[1] D1[2] D1[1] D1[2]
D2[1] D2[2] D2[1] D2[2]
D3[1] D3[2] D3[1] D3[2]
D4[1] D4[2] D4[1] D4[2]
A four drive RAID 10 mirror of
stripes
Stripe of Mirrors or
Mirror of Stripes – 4 or
more physical drives
More fault tolerant
than RAID 0, similar to
RAID 1
High overhead and
high disk usage
© 2006 Hewlett-Packard Development Company, L.P. The information contained
herein is subject to change without notice. The only warranties for HP products and
services are set forth in the express warranty statements accompanying such
products and services. Nothing herein should be construed as constituting an
additional warranty. HP shall not be liable for technical or editorial errors or
omissions contained herein.
439276-001, October 2006
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