Apple Xsan 2 (Third Edition) - Manual (Page 51)

51
Use Xsan Admin and related command-line tools to expand,
add, modify, check, and repair SAN volumes.
This chapter shows how you can expand an existing Xsan volume to provide more free
space. It also contains information about volume and storage pool settings, and shows
how to check and resolve volume integrity and fragmentation problems.
Adding Storage
To increase the storage on your SAN, you can:
Add volumes Â
Add storage pools to existing volumes Â
Add LUNs to existing storage pools Â
If you create a volume based on a custom volume type, you work directly with
storage pools. However, if you create a volume using a built-in Xsan volume type (for
example, General File Server or Podcast Producer Cluster), you don’t deal directly with
storage pools. Instead, you work with affinity tags that represent storage pools. Xsan
Admin organizes available LUNs into storage pools for you based on the performance
requirements of the chosen volume type.
Adding a storage pool to a volume increases available storage and also requires
Xsan Admin to stop the volume and unmount it. Adding storage pools is a quicker
way to expand a volume and doesn’t require defragmenting the volume to recover
performance.
Adding LUNs to a storage pool increases the size of an existing volume and can
improve performance by increasing the number of RAID controllers and data paths
between clients and storage. During the expansion, Xsan Admin stops the volume and
unmounts it from clients while it adds the new LUNs.
4
Managing SAN Storage