Apple Xsan 2 - Manual (Page 84)

Change the exclusivity of an affinity tag
The “Use for” affinity tag setting specifies the type of data—metadata, journaling, or
user data—a storage pool with that affinity can store. You choose the type of data
when you create a volume, and you can’t change the type of data an affinity stores
without recreating the volume.
If an affinity allows user data only, you can specify whether to allow only data that
has the matching affinity. If the data must have the matching affinity, the tag is called
“exclusive,” and data without the affinity isn’t allowed. You can change this setting as
needed.
Change the exclusivity of an affinity tag:
1 In Xsan Admin, select the storage pool in the Volumes pane and choose Edit Affinity
Settings from the Action pop-up menu (gear).
2 Click the checkbox to select or deselect “Only data with affinity.”
If the checkbox is deselected, this is the last affinity tag in the volume that isn’t
exclusive. A volume must contain at least one affinity tag that isn’t exclusive. In other
words, the volume must contain at least one affinity tag that accepts user data without
an affinity.
Set the storage pool stripe breadth
Xsan uses both the storage pool stripe breadth and the volume block allocation size
to decide how to write data to a volume. For most SANs, the default values for storage
pool stripe breadth and volume block allocation size result in good performance.
However, in some cases you might be able to improve read and write performance by
adjusting these values to suit a specific application.
The stripe breadth must be set when the volume is created; it can’t be changed for an
existing volume.
Set a storage pool’s stripe breadth:
When you create the volume, click the Settings button below the Affinity Tag list in the
m
Configure Volume Affinities pane of the setup assistant.
Maintain SAN volumes
Here are several volume maintenance tasks you can perform:
Rename a volume Â
See whether files or free space have become fragmented, and fix fragmentation. Â
If users have trouble accessing files, check the integrity of the volume, its metadata, Â
and its files, and make necessary repairs
Destroy a volume so you can use its LUNs in a different volume
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84 Chapter 5 Manage SAN storage