Meaning of iSCSI session states

Question

I see the below when I run "iscsiadm -m session -P3". However I'm not sure how to interpret.

    iSCSI Connection State: TRANSPORT WAIT
    iSCSI Session State: FREE
    Internal iscsid Session State: REOPEN

What is iSCSI connection state vs session state vs iscsid session state? What do those values assigned to them mean?

The state values seem to come from https://github.com/open-iscsi/open-iscsi/blob/d1d456cf28cd89c3a78c2bdb40f6950290ad2cd1/usr/session_info.c#L118. However, not sure when to expect each of them.

Answer 1

When the internal iscsid session state is REOPEN, it's trying to open a new session because the old one failed. The session is in TRANSPORT WAIT until the connection is established. If you're seeing it stuck in this state, it means that it can't open a TCP connection to the port on the target.

At this point, I'd typically pull out Wireshark and see what's going on. Typical problems include firewalling on the source or destination and the target offering iSCSI on a port other than 3260.