XenServer multipath configuration for LIO targets

XenServer multipath.conf with special support for LIO-based iSCSI targets to maximize multipath performance and ensures 100% stability. path_grouping_policy setting doesn’t seem to matter (between group_by_prio and multibus) in most basic setups. Invalid lines (as reported by XenServer 6.1) have also been removed.

http://djlab.com/stuff/xs61/multipath.conf

Specifically:

        device {
                vendor "LIO-ORG"
                product "*"
                path_grouping_policy group_by_prio
                path_checker tur
                getuid_callout "/sbin/scsi_id -g -u -s /block/%n"
                prio_callout "/sbin/mpath_prio_alua /dev/%n"
                path_selector "round-robin 0"
                hardware_handler "1 alua"
                rr_weight uniform
                rr_min_io 2
                failback immediate
        }