Databases Reference
In-Depth Information
Figure 13.5
Simple RAID 0 striping.
Figure 13.6
RAID 1.
13.7.4 RAID 2 and RAID 3
In RAID 0 and RAID 1 we discussed storing blocks of data. In contrast, RAID 2 intro-
duced the idea of storing data by bits, and streaming the bits in parallel into a demulti-
plexer that would combine the streams (Figure 13.8). This requires the disks to operate
in perfect synchronization. As a result this strategy is very good for single stream access,
but bad for multi-user access where users may be interested in different parts of the
data. Hamming codes are typically used in RAID 2 to do error correction. A Hamming
