Apple Xsan 1.0 - Manual (Page 14)

14 Chapter 1 Overview of Xsan
The following screen image shows how LUNs, storage pools, and volumes appear as
you organize them in the Xsan Admin application. This example shows a SAN named
“Test SAN” with a single shared volume named “SanVol.” Storage for the volume is
provided by two storage pools, “Pool1” and “Pool2,” each based on a single LUN. Each
of the LUNs is a 3-disk RAID 5 array on an Xserve RAID using 115 GB drive modules.
Folders With Affinities
To control which storage pool is used to store specific files (for example, to provide
different levels of service for different users or applications), you can associate a folder
on an Xsan volume with one of the storage pools that make up the volume.
If, for example, you set up storage pools with different balances of performance and
data redundancy, users can choose between faster and safer storage by putting files in
the appropriate folder.
In the illustration on page 12, a predefined folder has an affinity for the faster storage
pool that is based on RAID 0 arrays. Any file that a user copies into this folder is
automatically stored on the faster arrays. A second folder is associated with the more
secure RAID 5 storage.
Volume
Storage pool
LUN
SAN
LL0192.book Page 14 Thursday, July 29, 2004 5:20 PM