I.1.2
RAID 1 – Mirroring
In a
RAID 1
system, data is stored twice by writing to both a (set of) data disk(s)
and a (set of) mirror disk(s). If one disk fails, the controller uses either the data
disk or the mirror disk for data recovery and continues operation. You can only
use two disks for a RAID 1 array.
BLOCK 1
BLOCK 2
BLOCK 3
BLOCK 4
BLOCK 1
BLOCK 2
BLOCK 3
BLOCK 4
DISK 1
DISK 2
RAID 1
Mirroring
=
Figure I.2:
RAID 1 – Mirroring
Advantages
l
Offers excellent read speed and a write speed that is comparable to that
of a single disk.
l
If a disk fails and is replaced by a new disk, data does not have to be rebuilt;
it just has to be copied to the replacement disk.
l
RAID 1 is very simple technology.
Disadvantages
l
Volume size limited to one disk
l
Ineffective storage capacity; only half of the total disk capacity is available.
GEN3i
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I3763-3.1 en HBM: public