Aktywacja iSCSI multipathing w XenServer 5.5:

Do the following on each XenServer in the pool attaching to the AX4.

1. Disable STP on your SAN switches.
2. Verify that Multipath is enabled on XenServer.
3. On the XenServer console run "iscsiadm --mode discovery --type sendtargets --portal <san ip>"
4. On the XenServer console run "iscsiadm --mode node --loginall=all"
5. In Navisphere Manager open the "Connectivity Status..." box and register the new connections from the Xenserver. (There should be 2 connections for each SP in your AX4. It may take a little time for the connections to show up.)
6. In Navisphere Manager "Connect Hosts..." to the desired storage group.
7. On the XenServer Console add the following line to /etc/rc.d/rc.local
   
   iscsiadm --mode node --loginall=all &> /dev/null
    
8. On the XenServer console run "chkconfig open-iscsi on"
9. Reboot the xenserver and enjoy more than 1 active path.

 Źródło: http://forums.citrix.com/thread.jspa?threadID=248644&tstart=0