Apple Xsan 1.0 - Manual (Page 51)

Chapter 3 Managing SAN Storage 51
The Fibre Channel interface in an Xserve RAID caches up to 1 MB of data before
passing the data on to the RAID controller to be written to individual drive modules.
So, to minimize the time data spends waiting in the cache, you want to send data to
the Xserve RAID 1 MB at a time.
Setting the Selection Method for Multiple Connections
If there is more than one Fibre Channel connection to the LUNs in a storage pool, you
can choose whether Xsan uses one connection until it fails or rotates among the
connections. This is called the “multipath method.”
To change the multipath method:
1 In Xsan Admin, select the SAN the storage pool belongs to, click Setup, and click
Storage.
2 Double-click the storage pool in the list.
3 Choose a value from the Multipath Method pop-up menu.
Static: Xsan uses one connection until it fails, then switches to the second connection.
Rotate: Xsan switches to a different connection each time it writes data to the storage
pool. This can improve performance.
4 Click OK, then click Save.
From the Command Line
You can also set the multipath method using the
cvadmin multipath command in
Terminal. For more information, see the cvadmin man page or “Viewing or Changing
Volume and Storage Pool Settings (cvadmin)” on page 85.
LL0192.book Page 51 Thursday, July 29, 2004 5:20 PM