Lan-free iSCSI backups have intermittent failures resolved by a reboot of the vRanger server.
Luns show up in disk manager and look OK.
Windows 2008 R2 vRanger server using the Microsoft iSCSI initiator.
MPIO errors in the system event log showing connection drops.
Whne you bring up the iSCSI initiator, no targets are shown. After a reboot these connections are re-established.
Refer to microsoft support for specific event viewer error. This is an issue with the Microsoft iSCSI initiator/MPIO driver on the vRanger server.
Once this is resolved, Backups run normally.