March 2013 Dell EqualLogic Configuration Guide v14.1 4-35
4.5 Array RAID configurations and associated RAID sets
The tables show a logical drive layout when an array is initialized for the first time. The actual physical
layout of drives can change and evolve due to maintenance and administrative actions. Spare drives
can move as they are utilized to replace failed drives and newly added drives become the spares. It is
not possible to determine which physical drives are associated with each RAID set. This information is
dynamic and maintained by the EqualLogic firmware.
Table 15 shows the RAID set relationship for each RAID type in a 24-drive configuration.
Table 15 EqualLogic PS Series array RAID types and RAID set relationships
RAID policy Spare disks RAID set relationship Best practice
For selected configurations
RAID 5 1 Spare Disk (12+1) (9+1) Not for business critical data
Table 16 shows the RAID set relationship for each RAID type in a 48-drive configuration.
Table 16 EqualLogic PS Series array RAID types and RAID set relationships
Spare disks Raid set relationship Best practice
(6+1 ,6+,1, 6+1, 6+1, 6+1, 6+1) (3+1)
RAID 5 2 Spare
(12+1, 12+1, 12+1) (6+1) Not for business critical
Table 17 shows the RAID set relationship for each RAID type in a 16-drive configuration.
Table 17 EqualLogic PS Series array RAID types and RAID set relationships
Raid policy Spare disks Raid set relationship Best practice
For selected configurations
Not for business critical data