Problem with iSCSI connected tape drive

[perdrix]

I'm exporting the target (an HP Utrium 460 LTO-2 drive) from Starwind V8 (free).

From my Linux system (Ubuntu 16.04.1 with 4.8.13 kernel), I did:

Code: Select all

root@Charon:/home/amonra# mt -f /dev/st0 fsf 1
mt: /dev/st0: rmtioctl failed: Input/output error
root@Charon:/home/amonra#

The rmtioctl message appeared after about 10-15 seconds, and the iSCSI target showed that the session had dropped after about another 15 seconds or so.
When I was returned to the command line prompt some time later, the target showed the session as connected again.
During most/all of this time the forward space file operation was still running.

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root@Charon:/home/amonra# iscsiadm -m node --targetname "iqn.2008-08.com.starwindsoftware:mercury-ultrium2" --portal "192.168.129.77:3260" 
# BEGIN RECORD 2.0-873
node.name = iqn.2008-08.com.starwindsoftware:mercury-ultrium2
node.tpgt = -1
node.startup = manual
node.leading_login = No
iface.hwaddress = <empty>
iface.ipaddress = <empty>
iface.iscsi_ifacename = default
iface.net_ifacename = <empty>
iface.transport_name = tcp
iface.initiatorname = <empty>
iface.bootproto = <empty>
iface.subnet_mask = <empty>
iface.gateway = <empty>
iface.ipv6_autocfg = <empty>
iface.linklocal_autocfg = <empty>
iface.router_autocfg = <empty>
iface.ipv6_linklocal = <empty>
iface.ipv6_router = <empty>
iface.state = <empty>
iface.vlan_id = 0
iface.vlan_priority = 0
iface.vlan_state = <empty>
iface.iface_num = 0
iface.mtu = 0
iface.port = 0node.discovery_address = 192.168.129.77
node.discovery_port = 3260
node.discovery_type = send_targets
node.session.initial_cmdsn = 0
node.session.initial_login_retry_max = 8
node.session.xmit_thread_priority = -20
node.session.cmds_max = 128
node.session.queue_depth = 32
node.session.nr_sessions = 1
node.session.auth.authmethod = None
node.session.auth.username = <empty>
node.session.auth.password = <empty>
node.session.auth.username_in = <empty>
node.session.auth.password_in = <empty>
node.session.timeo.replacement_timeout = 120
node.session.err_timeo.abort_timeout = 15
node.session.err_timeo.lu_reset_timeout = 30
node.session.err_timeo.tgt_reset_timeout = 30
node.session.err_timeo.host_reset_timeout = 60
node.session.iscsi.FastAbort = Yes
node.session.iscsi.InitialR2T = No
node.session.iscsi.ImmediateData = Yes
node.session.iscsi.FirstBurstLength = 262144
node.session.iscsi.MaxBurstLength = 16776192
node.session.iscsi.DefaultTime2Retain = 0
node.session.iscsi.DefaultTime2Wait = 2
node.session.iscsi.MaxConnections = 1
node.session.iscsi.MaxOutstandingR2T = 1
node.session.iscsi.ERL = 0
node.conn[0].address = 192.168.129.77
node.conn[0].port = 3260
node.conn[0].startup = manual
node.conn[0].tcp.window_size = 524288
node.conn[0].tcp.type_of_service = 0
node.conn[0].timeo.logout_timeout = 15
node.conn[0].timeo.login_timeout = 15
node.conn[0].timeo.auth_timeout = 45
node.conn[0].timeo.noop_out_interval = 5
node.conn[0].timeo.noop_out_timeout = 5
node.conn[0].iscsi.MaxXmitDataSegmentLength = 0
node.conn[0].iscsi.MaxRecvDataSegmentLength = 262144
node.conn[0].iscsi.HeaderDigest = None
node.conn[0].iscsi.DataDigest = None
node.conn[0].iscsi.IFMarker = No
node.conn[0].iscsi.OFMarker = No
# END RECORD
root@Charon:/home/amonra#

Any guidance on fixing this will be greatly appreciated.

Thanks, Dave

[perdrix]

I installed 8.0.0.9996 and re-created the preblem with debug logging enabled.

I tried to attach the log file but was told "The extension log is not allowed". I also tried it as a txt file How do I get this log to you?

I don't understand quite why the session continually opens and closes ...

Dave

[perdrix]

I just ran a Wireshark capture on the target system of the iSCSI session for a Windows initiator connecting the tape and then issuing an FSF. I then did the same for the Ubuntu open-iscsi initiator.

The capture for the WIndows initiator looks pretty much as I would expect (given my limited knowledge of the iSCSI protocols).

The Ubuntu/open-iscsi capture has all sorts of odd stuff like logins being sent to the target every 15 seconds whle the FSF is being processed. This doesn't seem right somehow

Do you think you could confirm my suspicions and also indicate if you know of anything I could try on the Ubuntu system to resolve this?

I've also uploaded the log file from my earlier post which I've zipped up.

Many thanks
Dave

[Michael (staff)]

Hello Dave,
Thank you for the logs.
Our R&D department already works on it. We will update you soon.

[perdrix]

The problem relates to open-iscsi trying to send iSCI NOPOut requests while the target is busy processing the FSF request.

I've changed the initiator settings to prevent it using the iSCSI NOPOut polling by setting:

node.conn[0]timeo.noop_out_interval=0
node.conn[0]timeo.noop_out_timeout=0

See the open-iscsi google group for more about this.

Dave

[Michael (staff)]

Hello Dave,
Thank you for this information.
Happy New Year!