98 Configuring PERC 3
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Using the Array Configuration Planner

Table 7-12 lists RAID levels, fault tolerance, and effective capacity for some

possible drive configurations for an array consisting of one to 32 drives. This

table does not take into account any hot spare (standby) drives. You should

always have a hot spare drive in case of drive failure. RAID 1 requires two

drives. RAID 5 requires at least three drives. RAID 10 requires at least four

drives. RAID 50 requires at least six drives.

Table 7-12. Array Configuration Planner
Number
of Drives
Possible RAID
Levels
Relative
Performance
Fault
Tole ranc e
Effective
Capacity
1 RAID 0 Excellent No 100%
2 RAID 0 Excellent No 100%
2 RAID 1 Good Yes 50%
3 RAID 0 Excellent No 100%
3 RAID 5 Good Yes 67%
4 RAID 0 Excellent No 100%
4 RAID 5 Good Yes 75%
4 RAID 10 Good Yes 50%
5 RAID 0 Excellent No 100%
5 RAID 5 Good Yes 80%
6 RAID 0 Excellent No 100%
6 RAID 5 Good Yes 83%
6RAID 10
(spanned)
Excellent Yes 50%
6RAID 50
(spanned)
Good Yes 67%
7 RAID 0 Excellent No 100%
7 RAID 5 Good Yes 86%
8 RAID 0 Excellent No 100%
8 RAID 5 Good Yes 87%
8RAID 10
(spanned)
Excellent Yes 50%