Raid 1(0+1) - Acer Altos RAIDWatch Manual

In disk mirroring, the total disk capacity is equivalent to half the sum of the capacities of all SCSI
drives in the combination. Thus, combining four 250GB SATA drives, for example, would create a
single logical drive with a total disk capacity of 1TB. This combination of drives appears to the
system as a single logical drive.
RAID 1 is simple and easy to implement; however, it is more expensive as it doubles the investment
required for a non-redundant disk array implementation.
Block 1
Block 2
Block 3
Block 4
Block 5
Block 6
Block 7
Block 8
In addition to the data protection RAID 1 provides, this RAID level also improves performance. In
cases where multiple concurrent I/Os are occurring, these I/Os can be distributed between two disk
copies, thus reducing total effective data access time.
C.5 RAID 1(0+1)
RAID 1(0+1) combines RAID 0 and RAID 1 – Mirroring and Disk Striping. RAID (0+1) allows multiple
drive failure because of the full redundancy of the hard disk drives. If more than two hard disk
drives are chosen for RAID 1, RAID (0+1) will be performed automatically.
Important RAID (0+1) will not appear in the list of RAID levels supported by the controller. If you wish to
perform RAID 1, the controller will determine whether to perform RAID 1 or RAID (0+1). This will
depend on the drive number that has been selected for the logical drive.
Block 1
Block 2
Block 3
Block 4
Block 5
Block 6
Block 7
Block 8
Block 1 Block 1
Block 2 Block 2
Block 3 Block 3
Block 4 Block 4
Block 1 Block 2
Block 3 Block 4
Block 5 Block 6
Block 7 Block 8
Mirror 1 Mirror 2
Mirror 3 Mirror 4
Mirror 5 Mirror 6
Mirror 7 Mirror 8
RAID Levels
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