Apple Xsan 1.4 - Manual (Page 66)

66 Chapter 2 Setting Up a Storage Area Network
 Use for: Choose the type of data to store in the storage pool. Journal data is used by
the controller to ensure the integrity of files in the volume. Metadata is file system
information used by the controller. Journal data and metadata are always stored at
least on the first storage pool in a volume. If this is not the first storage pool in the
volume, you can choose “User data only.” To allow only files saved in a folder that has
an affinity for this storage pool, enable “Only data with affinity.”
 Stripe Breadth: Unless you have calculated a different value for performance tuning,
leave this set to the default (256 blocks). Otherwise, change this number to the
amount of data written, in turn, to each LUN in the storage pool. For optimum
performance with Xserve RAID systems, the stripe breadth multiplied by the block
allocation size (which you set for the volume) should equal 1 MB (1,048,576 bytes).
For more information, see “Choosing Stripe Breadth for a Storage Pool” on page 93.
 Multipath Method: If you have two Fibre Channel connections between each client
computer and Xserve RAID system, choose how Xsan uses the connections. Choose
Rotate to have Xsan alternate between the connections for maximum throughput.
Choose Static to have Xsan assign each LUN in the storage pool alternately to one of
the connections when the volume is mounted.
3 Click OK to return to the list.
4 Repeat for each storage pool you need.