Apple Xsan 1.4 - Manual (Page 23)

Chapter 1 Overview of Xsan 23
How Xsan Storage Is Organized
Users use an Xsan volume the same way they use a local disk. What they don’t see is
that the SAN volume actually consists of numerous physical disks combined on several
levels using RAID techniques.
The following illustration shows an example of how disk space provided by the
individual drive modules in several Xserve RAID systems is combined into a volume
that users see as a large local disk.
Faster
Safer
Storage pool
(Striping)
RAID 0
array
RAID 0
array
LUN LUN
RAID 0
array
RAID 0
array
LUN LUN
Shared
SAN volume
Affinity Affinity
RAID 5
array
RAID 5
array
LUN LUN
RAID 5
array
RAID 5
array
LUN LUN
Storage pool
(Striping)