I use Openfiler as an iSCSI target for some dev servers, it gives me the ability to utilize some hard drives in an old Dell Poweredge 2550 server I have in my rack. It's not a bad box for using as a cheap low-performance SAN, since it has built in gigabit ethernet support on one NIC that's supported by Openfiler along with another 10/100 NIC that's also supported. I use the 10/100 for the admin interface and the Gigabit NIC to talk to my servers.
Anyhow, I'm always reconfiguring this thing, removing volumes and targets, etc. Openfiler is terribly buggy with the deletion aspects of things, often leaving stuff in config files. Today I was "clearing" the box down, and inadvertantly was left with no volumes yet I still had an iSCSI target defined pointing to a nonexistent volume. That last iSCSI target I was unable to remove through the web GUI.
So, the trick is to get a console on the box, and dig into the following file:
/opt/openfiler/etc/volumes.xml
You'll open it up and find something like this:
<?xml version="1.0" ?>
<volumes>
<volume id="iscsi-1" name="First Target" mountpoint="/mnt/volgroup1/iscsi-i/" vg="volgroup1" fstype="xfs" />
</volumes>
That volume id on the 3rd line is the thing that has to go. Fire up a text editor, remove that line (leave the rest intact), and save the file. Refresh your gui and start adding volumes now and the iSCSI targets won't be stuck anymore.