125
RAID Level Comparsion
RAID Level
Description
Disks
Requirement
(Minimum)
Data
Availability
0
Also known as striping. Data distributed across multiple drives in the
array. There is no data protection.
1
No data
Protection
1
Also known as mirroring. All data replicated on 2 separated disks. N is
almost always 2. Due to this is a 100 % duplication, so is a high costly
solution.
2
Up to one
disk failure
10(1E)
Also known as mirroring and striping. Data is written to two disks
simultaneously, and allows an odd number or disk. Read request can
be satisfied by data read from wither one disk or both disks.
3
Up to one
disk failure
in each
sub-volume
3
Also known Bit-Interleaved Parity. Data and parity information is
subdivided and distributed across all data disks. Parity information
normally stored on a dedicated parity disk.
3
Up to one
disk failure
5
Also known Block-Interleaved Distributed Parity. Data and parity
information is subdivided and distributed across all disk. Parity
information normally is interspersed with user data.
3
Up to one
disk failure
6
RAID 6 provides highest reliability, but not widely used. Similar to
RAID 5, but does two different parity computations or the same
computation on overlapping subsets of the data. The RAID 6 can offer
fault tolerance greater that RAID 1 or RAID 5 but only consumes the
capacity of 2 disk drives for distributed parity data.
4
Up to two
disk failure
30
RAID 30 is a combination multiple RAID 3 volume sets with RAID 0
(striping)
6
Up to one
disk failure
in each
sub-volume
50
RAID 50 is a combination multiple RAID 5 volume sets with RAID 0
(striping)
6
Up to one
disk failure
in each
sub-volume
60
RAID 60 is a combination multiple RAID 6 volume sets with RAID 0
(striping)
8
Up to two
disk failure
in each
Summary of Contents for ES208X12HP
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