iscsiadm error "Could not load transport iser"

[Luis Navarro]

Hi all,

I'm trying to test a new Ubuntu 22.04.1 LIO iSCSI target with iscsiadm 2.1.5 (installed via "apt").  iscsiadm works fine over "tcp" transport but always fails over the "iser" transport with the following error:

iscsiadm: Could not load transport iser.Dropping interface iface0.

Here are the commands I ran:

$ sudo iscsiadm -m iface -I iface0 --op=new
$ sudo iscsiadm -m iface -I iface0 -o update -n iface.transport_name -v iser
$ sudo iscsiadm -m discovery -t st -p 192.168.25.5:3260 -I iface0 -d 8
iscsiadm: Max file limits 1024 1048576
iscsiadm: updating defaults from '/etc/iscsi/iscsid.conf'
iscsiadm: updated 'discovery.sendtargets.iscsi.MaxRecvDataSegmentLength', '32768' => '32768'
iscsiadm: updated 'node.startup', 'manual' => 'manual'
iscsiadm: updated 'node.leading_login', 'No' => 'No'
iscsiadm: updated 'node.session.timeo.replacement_timeout', '120' => '120'
iscsiadm: updated 'node.conn[0].timeo.login_timeout', '30' => '15'
iscsiadm: updated 'node.conn[0].timeo.logout_timeout', '15' => '15'
iscsiadm: updated 'node.conn[0].timeo.noop_out_interval', '5' => '5'
iscsiadm: updated 'node.conn[0].timeo.noop_out_timeout', '5' => '5'
iscsiadm: updated 'node.session.err_timeo.abort_timeout', '15' => '15'
iscsiadm: updated 'node.session.err_timeo.lu_reset_timeout', '30' => '30'
iscsiadm: updated 'node.session.err_timeo.tgt_reset_timeout', '30' => '30'
iscsiadm: updated 'node.session.initial_login_retry_max', '4' => '8'
iscsiadm: updated 'node.session.cmds_max', '128' => '128'
iscsiadm: updated 'node.session.queue_depth', '32' => '32'
iscsiadm: updated 'node.session.xmit_thread_priority', '-20' => '-20'
iscsiadm: updated 'node.session.iscsi.InitialR2T', 'No' => 'No'
iscsiadm: updated 'node.session.iscsi.ImmediateData', 'Yes' => 'Yes'
iscsiadm: updated 'node.session.iscsi.FirstBurstLength', '262144' => '262144'
iscsiadm: updated 'node.session.iscsi.MaxBurstLength', '16776192' => '16776192'
iscsiadm: updated 'node.conn[0].iscsi.MaxRecvDataSegmentLength', '262144' => '262144'
iscsiadm: updated 'node.conn[0].iscsi.MaxXmitDataSegmentLength', '0' => '0'
iscsiadm: updated 'node.session.nr_sessions', '1' => '1'
iscsiadm: updated 'node.session.reopen_max', '0' => '0'
iscsiadm: updated 'node.session.iscsi.FastAbort', 'Yes' => 'Yes'
iscsiadm: updated 'node.session.scan', 'auto' => 'auto'
iscsiadm: looking for iface conf /etc/iscsi/ifaces/iface0
iscsiadm: updated 'iface.iscsi_ifacename', 'iface0' => 'iface0'
iscsiadm: updated 'iface.prefix_len', '0' => '0'
iscsiadm: updated 'iface.transport_name', '' => 'iser'
iscsiadm: updated 'iface.vlan_id', '0' => '0'
iscsiadm: updated 'iface.vlan_priority', '0' => '0'
iscsiadm: updated 'iface.iface_num', '0' => '0'
iscsiadm: updated 'iface.mtu', '0' => '0'
iscsiadm: updated 'iface.port', '0' => '0'
iscsiadm: updated 'iface.tos', '0' => '0'
iscsiadm: updated 'iface.ttl', '0' => '0'
iscsiadm: updated 'iface.tcp_wsf', '0' => '0'
iscsiadm: updated 'iface.tcp_timer_scale', '0' => '0'
iscsiadm: updated 'iface.def_task_mgmt_timeout', '0' => '0'
iscsiadm: updated 'iface.erl', '0' => '0'
iscsiadm: updated 'iface.max_receive_data_len', '0' => '0'
iscsiadm: updated 'iface.first_burst_len', '0' => '0'
iscsiadm: updated 'iface.max_outstanding_r2t', '0' => '0'
iscsiadm: updated 'iface.max_burst_len', '0' => '0'
iscsiadm: in read_transports
iscsiadm: Adding new transport tcp
iscsiadm: Matched transport tcp
iscsiadm: sysfs_attr_get_value: open '/class/iscsi_transport/tcp'/'handle'
iscsiadm: sysfs_attr_get_value: open '/class/iscsi_transport/tcp'/'caps'
iscsiadm: in read_transports
iscsiadm: Updating transport tcp
iscsiadm: sysfs_attr_get_value: open '/class/iscsi_transport/tcp'/'handle'
iscsiadm: sysfs_attr_get_value: open '/class/iscsi_transport/tcp'/'caps'
iscsiadm: Could not load transport iser.Dropping interface iface0.

Looking at the /sys/class/iscsi_transport and /sys/devices/virtual/iscsi_transport directories on the client system, I only see "tcp".  Should I also be seeing "iser"?  Is there an extra package I need to install or step I need to take to get "iser" devices under the "iscsi_transport" directory?

Thanks!
Luis

[The Lee-Man]

The iser transport is only supported for some cards. It's normally an infiniband transport.

Do you have a CNA card (and infrastructure) that supports iser?

[Luis Navarro]

I'm using two ConnectX-5 Ethernet cards (MCSX515A-CCAT) direct connected with a QSFP28 DAC.

FWIW, after I submitted my question, I *think* I got ISER to work with the same target but using ESXi 6.7 as the initiator.  But I'd still like to use iscsiadm for debugging.

My best guess is that I need to install an optional Ubuntu package to get those "iser" devices under the "iscsi_transport" directory?