iSCSI troubleshooting

I have an Equallogic SAN that I connect to from AIX (as well as Windows)

I had configured the connection and created the volumes and filesystems and all was working great.

Then one day, no communication between the SAN and the AIX (I can ping though) Anything I do on the AIX box at this time just struggles as it must be trying to talk with the SAN, but apparently unable.

Logging into the SAN from a Windows box tells me the SAN is functioning properly. However, I see that the AIX is no longer logged into the SAN. Now AIX still thinks it has the disk, VG, and filesystems are all there, but cannot communicate with them.

At that point, how do I force the AIX to retry the login to get it to re-establish the connection to the SAN?

Also, any ideas what would cause the loss off connection?

Is this an ISCSI NAS unit or is it really SAN with a fibre connection. If it is ISCSI NAS then how are you connecting the NAS unit, with ethernet?

It is a SAN via Ethernet. Set up the iSCSI requester, but not on an iSCSI adapter, just an Ethernet adapter that runs iSCSI protocol.

The disk is shown as iSCSI device. Upon which I created the volume group, and filesystems. (not an NFS share or any think like that, all Unix native.)

When the problem occurs, the SAN says AIX is not logged into the SAN (No connection - requester security is minimal, I only restrict by IP - but I could change that to IQN name. But I'm not using CHAP or any other password authentication.)
At the same time, AIX shows the file systems on the SAN as mounted. Shows the VG as active and the disk as there. An attempt to dismount the filesystem or any other activity is usually followed with a long timeout or hanging process. Sometimes I get device not responding messages.

If I could figure out how to get the AIX to re-establish the connection to the SAN, I would assume at that point I could then mount / dismount. filesystems.