How to Identify if your iSCSI Storage Repository has Changed SCSI IDs

Useful if you encounter an issue repairing an SR with error code SR_BACKEND_FAILURE_19 no such devices.

http://support.citrix.com/article/CTX118641

Some Useful iSCSI Commands

To discover targets at a given IP address:
iscsiadm -m discovery --type sendtargets --portal

To login to the one of the targets found by the command above:
iscsiadm --mode node --targetname --portal --login

To view all active sessions and connections:
iscsiadm --mode session

XenServer - SR_BACKEND_FAILURE List of error codes and their description

A full list of all error codes and their description is available in the /opt/xensource/sm/XE_SR_ERRORCODES.xml file