I have 2 RHEL 5.X servers. The first server is running has my oracle database and some other content is located and the iscsi LUN. I take a smart clone of that lun, map it to another server and back up the smartclone.
next day I umount the smartclone from the backup server, unassign the smart clone from the backup server, restart the iscsid on the backup server, delete the smartclone, create a new smartclone, rerun the new initiator string and mount the drive I get a resource error that will not clear on the backup server until it is rebooted.
Sounds like the iSCSI session is not terminated despite the LUN being unmounted. I forget the commands to check the session in linux, maybe iscsiutil -p? See if there is an option in the iscsiutil to terminate the session or logout.
Hopefully a seasoned linux person will chime in, but I'm pretty sure the reboot is terminating the session and that's why it fixes your problem.
