User manual

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Appendix A: RAID Concepts
RAID
RAID is an acronym that stands for Redundant Array of Independent Disks. It is
divided into different numbered Levels. The numbers of these Levels do not
mean that one Level is higher or better than another. Each Level has its own
advantages and shortcomings.
PAM allows you to select the RAID Level when you create an Array. The
available RAID Level selection depends on which Promise product you have
and the number of disk drives available.
The table below lists the RAID Levels obtainable with FastTrak TX Series.
RAID Level Name
Minimum
drives
Maximum
drives
0 Striping 1 4
1 Mirroring 2 2
0+1 Striping + Mirroring 4 4
Table 4. RAID Levels for the FastTrak TX series.
Following is a discussion how these RAID Levels work.
RAID 0
RAID 0 is a method of striping, or
writing data over two or more hard
disks at the same time. Multiple disks
can read and write data faster than
one. However, there is no data
redundancy with this arrangement, so
if one disk fails, all your data is lost.
1
3
5
7
2
4
6
8
Disk Drives
Data
Stripe