Array Definition; Raid Set; Volume Set - Sans Digital Mobileraid MR8X Detailed User's Manual

SAS-to-SATA II RAID Subsystem

1.5 Array Definition

1.5.1 Raid Set

A Raid Set is a group of disk drives containing one or more logical volumes called Volume
Sets. It is not possible to have multiple Raid Sets on the same disk drives.
A Volume Set must be created either on an existing Raid Set or on a group of available
individual disk drives (disk drives that are not yet a part of a Raid Set). If there are
existing Raid Sets with available raw capacity, new Volume Set can be created. New
Volume Set can also be created on an existing Raid Set without free raw capacity by
expanding the Raid Set using available disk drive(s) which is/are not yet Raid Set member.
If disk drives of different capacity 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.

1.5.2 Volume Set

A Volume Set is seen by the host system as a single logical device. It is organized in a
RAID level with one or more physical disks. RAID level refers to the level of data
performance and protection of a Volume Set. A Volume Set capacity can consume all or
a portion of the r a w capacity available in a Raid Set. Multiple Volume Sets can exist on
a group of disks in a Raid Set. Additional Volume Sets created in a specified Raid Set will
reside on all the physical disks in the Raid Set. Thus each Volume Set on the Raid Set will
have its data spread evenly across all the disks in the Raid Set. Volume Sets of different
RAID levels may coexist on the same Raid Set.
In the illustration below, Volume 1 can be assigned a RAID 5 level while Volume 0 might be
assigned a RAID 0+1 level.
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Installation and Configuration Manual