iSCSI > open-iscsi

Debian as an iSCSI Initiator

This page focus on the open-iscsi.org Initiator (package open-iscsi). Remiinder : the initiator is the "client".

Quickstart

1. Install the software

The module in iscsi_tcp is shipped in Debian/Etch's standard kernel. So you'll just have to install open-iscsi, configure 6 lines in /etc/iscsi/iscsid.conf :

discovery.sendtargets.auth.authmethod = CHAP
discovery.sendtargets.auth.username = jdoe
discovery.sendtargets.auth.password = YourSecurePwd1
node.session.auth.authmethod = CHAP
node.session.auth.username = jdoe
node.session.auth.password = YourSecurePwd1

and may be :

node.startup = automatic

Otherwise, you can also create a single connexion (a file /etc/iscsi/nodes/iqn.2007-01.org.debian.foobar:CDs/192.168.0.1,3260 is automatically created)

iscsiadm   --mode node  --targetname "iqn.2007-01.org.debian.foobar:CDs"  -p 192.168.0.1:3260 --op=update --name node.session.auth.authmethod --value=CHAP
iscsiadm   --mode node  --targetname "iqn.2007-01.org.debian.foobar:CDs"  -p 192.168.0.1:3260 --op=update --name node.session.auth.username --value=$Id
iscsiadm   --mode node  --targetname "iqn.2007-01.org.debian.foobar:CDs"  -p 192.168.0.1:3260 --op=update --name node.session.auth.password --value=$MDP
iscsiadm   --mode node  --targetname "iqn.2007-01.org.debian.foobar:CDs"  -p 192.168.0.1:3260 --login

Using

Let's query the target (server) about the service it knows

iscsiadm  -m discovery -t st -p 192.168.0.20
192.168.0.1:3260,1 iqn.2007-01.org.debian.foobar:CDs
192.168.0.1:3260,1 iqn.2007-01.org.debian.foobar:USB

Next let's open a session to a given Target :

iscsiadm  -m node  --targetname "iqn.2007-01.org.debian.foobar:CDs" --portal "192.168.0.1:3260" --login

You can then mount the new device, but under most situation, you will want to use LABEL= syntax in /etc/fstab (see e2label).

#device         mount point     FS      Options Backup  fsck
LABEL=data1     /mnt/data1      ext3    _netdev 0       0

Once you have finished working, you can release the iSCSI target.

iscsiadm  -m node  --targetname "iqn.2007-01.org.debian.foobar:CDs" --portal "192.168.0.1:3260" --logout

FAQ & common error messages

ietd: CHAP initiator auth.: No valid user/pass combination for initiator iqn.1993-08.org.debian:01:123456789abcd found

The initiator's user account and/or password is wrong !

iscsiadm: Login failed to authenticate with target
iscsiadm: discovery login to 192.168.0.20 rejected: initiator error (02/01), non-retryable, giving up ::wrong "discovery" username or password.

How does udev looks like ?

udev won't help you mounting the device. use "LABEL=" in /etc/fstab instead.

$ udevinfo -a -p $(udevinfo -q path -n /dev/sdb)
  looking at parent device '/devices/platform/host98/session1/target98:0:0/98:0:0:2':
    KERNELS=="98:0:0:2"
    SUBSYSTEMS=="scsi"
    DRIVERS=="sd"
    ATTRS{modalias}=="scsi:t-0x00"
    ATTRS{ioerr_cnt}=="0x0"
    ATTRS{iodone_cnt}=="0x1f"
    ATTRS{iorequest_cnt}=="0x1f"
    ATTRS{iocounterbits}=="32"
    ATTRS{timeout}=="30"
    ATTRS{state}=="running"
    ATTRS{rev}=="0   "
    ATTRS{model}=="VIRTUAL-DISK    "
    ATTRS{vendor}=="IET     "
    ATTRS{scsi_level}=="5"
    ATTRS{type}=="0"
    ATTRS{queue_type}=="none"
    ATTRS{queue_depth}=="32"
    ATTRS{device_blocked}=="0"

Debian as an iSCSI Initiator

Quickstart

1. Install the software

Using

FAQ & common error messages

See also