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APPENDIX
Appendix E
RAID Concept
RAID Set
A RAID set is a group of disks connected to a RAID subsystem. A
RAID set contains one or more volume sets. The RAID set itself
does not define the RAID level (0, 1, 10, 1E, 3, 5, and 6, etc); the
RAID level is defined within each volume set. Therefore, volume
sets are contained within RAID sets and RAID Level is defined
within the volume set. If physical disks of different capacities are
grouped together in a RAID set, then the capacity of the smallest
disk will become the effective capacity of all the disks in the RAID
set.
Volume Set
Each volume set is seen by the host system as a single logical
device (in other words, a single large virtual hard disk). A volume
set will use a specific RAID level, which will require one or more
physical disks (depending on the RAID level used). RAID level
refers to the level of performance and data protection of a volume
set. The capacity of a volume set can consume all or a portion
of the available disk capacity in a RAID set. Multiple volume sets
can exist in a RAID set. For the RAID subsystem, a volume set
must be created either on an existing RAID set or on a group of
available individual disks (disks that are about to become part
of a RAID set). If there are pre-existing RAID sets with available
capacity and enough disks for the desired RAID level, then the
volume set can be created in the existing RAID set of the user’s
choice.