iscsid: Kernel reported iSCSI connection 8:0 error (1021 - ISCSI_ERR_SCSI_EH_SESSION_RST: Session was dropped as a result of SCSI error recovery) state (3)

[w00s...@gmail.com]

I have a Synology DS1511+ NAS where I have 4 logical volumes shared via iscsi.
2 of these are OCFS2 partitions, 2 are truecrypt encrypted partitions.

I have lately started seeing errors such as :
iscsid: Kernel reported iSCSI connection 8:0 error (1021 - ISCSI_ERR_SCSI_EH_SESSION_RST: Session was dropped as a result of SCSI error recovery) state (3)
followed by:
kernel: [  121.788507]  connection7:0: detected conn error (1020)
iscsid: conn 0 login rejected: target error (03/01)

If I log out from the target, I can see the connection remains on the target and I have to reboot the NAS in order to clear out the failed connection.

I have no idea how to resolve this issue, I have tried to reboot both NAS and my PC but the problem persists. I have a few times managed to get the connection to work again but it often results in, when trying to write to the disk, errors such as:
kernel: [111409.202318]  connection5:0: detected conn error (1020)
iscsid: Kernel reported iSCSI connection 5:0 error (1020 - ISCSI_ERR_TCP_CONN_CLOSE: TCP connection closed) state (3)
iscsid: connection5:0 is operational after recovery (1 attempts)
followed by a reboot!

That is even worse than the connection issue as there should be no reason for a panic reboot when an iscsi connection goes down. This is a really nasty bug which has caused me to lose work.

How to diagnose these issues?
What can I do to fix the problem?

[Michael Christie]

On Dec 8, 2013, at 8:39 PM, w00s...@gmail.com wrote:

> I have a Synology DS1511+ NAS where I have 4 logical volumes shared via iscsi.
> 2 of these are OCFS2 partitions, 2 are truecrypt encrypted partitions.
>
> I have lately started seeing errors such as :
> iscsid: Kernel reported iSCSI connection 8:0 error (1021 - ISCSI_ERR_SCSI_EH_SESSION_RST: Session was dropped as a result of SCSI error recovery) state (3)
> followed by:
> kernel: [ 121.788507] connection7:0: detected conn error (1020)
> iscsid: conn 0 login rejected: target error (03/01)

Something is going wrong on the target side. Check its logs. The iscsi initiator 1021 error means that scsi commands took longer than the disk command timeout. The scsi error layer error handler ran and it could not fix the problem. We then tried to religion o the target but the target is returning 03/01 which means the iscsi service/target is not operational.