Toshiba Magnia 560S - Manual (Page 42)

RAID Levels 24
RAID Levels
Table 3.2 describes the factors you need to consider when selecting a RAID level.
Table 3.2 Factors for Selecting RAID Levels
Level Description and
Use Pros Cons Maximum
Number of
Physical
Drives Fault
Tolerant
0 Data divided in
blocks and
distributed
sequentially
(pure striping).
Use for non-
critical data that
requires high
performance. High data
throughput
for large
files No fault
tolerance.
All data lost
if any drive
fails. One to 15 No
1 Data duplicated
on another disk
(mirroring). Use
for read-
intensive fault-
tolerant systems. 100% data
redundancy Doubles
disk space.
Reduced
performance
during
rebuilds. Two Yes
5 Disk striping and
parity data across
all drives. Use for
high read volume
but low write
volume, such as
transaction
processing. Achieves
data
redundancy
at low cost Performance
not as good
as RAID 1 Three to 15 Yes
10 Data striping and
mirrored drives. High data
transfers,
complete
redundancy More
complicated Four to 14
(must be a
multiple of
two) Yes
50 Disk striping and
parity data across
all drives. High data
transfers,
redundancy More
complicated Six to 15 Yes
NOTE: The maximum number of physical drives supported by the SCSI
320-1 controller is 15.