Specifications

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RAID Level 1
RAID Level 1 ensures the security of data by writing
the exact same data simultaneously to two different
drives. With RAID Level 1, the host sees what it
believes to be a single physical drive of a specific size:
it does not know about the mirrored pair.
This application is used for critical data which cannot
be at risk to be lost or corrupted due to the failure of a
single drive.
The ATTO FastStream supports an even number of 2
to16 drives per RAID Level 1 group.
Exhibit A-4 RAID Level 1: Data is written to two drives
simultaneously. The duplicated data is represented by
the shaded blocks.
RAID Level 1 plus additional mirroring
RAID Level 1 with multiple mirrors uses at least 3
drives with the same data on each drive. This
application offers the highest fault-tolerance with good
performance, especially for small database
applications.
Exhibit A-5 RAID Level 1 plus mirrors: Data is written to
two or more drives simultaneously. The duplicated data is
represented by the shaded blocks.
RAID Level 1+0
RAID Level 1+0 increases data transfer rates while
ensuring security by writing the exact same data
simultaneously to two or more different drives.
RAID Level 1+0 is used in applications requiring high
performance and redundancy, combining the
attributes of RAID Levels 1 and 0.
The ATTO FastStream supports an even number of 4
to 16 drives per RAID Level 1+0 group.
Exhibit A-6 RAID Level 1+0 with mirroring and
spanning; redundancy is shown by the shaded blocks.
RAID Level 4
RAID 4 writes data across multiple drives or devices
(striping) with parity blocks written to a single drive in
the RAID group. This increases reliability while using
fewer drives than mirroring.
RAID Level 4 is best suited for applications that
perform mostly sequential access such as video
applications.
You must have at least three drives to set up RAID
Level 4.
Exhibit A-7 RAID Level 4 uses block striping and one
drive for parity. The parity drive is shaded.
RAID Level 5
RAID Level 5 increases reliability while using fewer
drives than mirroring by using parity redundancy:
parity is distributed across multiple drives.
The ATTO FastStream supports 3 to 16 drives per
RAID Level 5 group.
Exhibit A-8 RAID Level 5 with parity blocks shaded.
RAID Level 1
Stripe Disk 0 Disk 1 Disk 2 Disk 3 Disk 4 Disk 5
0D0D0 D4 D4 D8 D8
1D1
D1 D5 D5 D9 D9
2D2
D2 D6 D6 D10 D10
3D3
D3 D7 D7 D11 D11
RAID Level 1
Stripe Disk 0 Disk 1 Disk 2 Disk 3 Disk 4 Disk 5
0D0D0 D0 D4 D4 D4
1D1
D1 D1 D5 D5 D5
2D2D2 D2 D6 D6 D6
3D3
D3 D3 D7 D7 D7
RAID Level 1+0
Stripe Disk 0 Disk 1 Disk 2 Disk 3
0D0D0 D1 D1
1D2
D2 D3 D3
2D4
D4 D5 D5
3D6
D6 D7 D7
RAID Level 4
Stripe Disk 0 Disk 1 Disk 2 Disk 3
0 D0D1D2P 0-2
1 D3D4D5
P 3-5
2 D6D7D8
P 6-8
RAID Level 5
Stripe Disk 0 Disk 1 Disk 2 Disk 3
0 D0D1D2P 0-2
1D3D4
P 3-5 D5
2D6
P 6-8 D7 D8
3
P 9-11 D9 D10 D11