Linux Connect to an iSCSI Volume

Q. How do I format and connect to an iSCSI Volume under Debian / Ubuntu Linux?

A. You need to install open-iscsi package for high performance, transport independent iSCSI implementation under Debian / Ubuntu Linux. This package is also known as the Linux Open-iSCSI Initiator. You need Linux operating system with kernel version 2.6.16, or later. See REHL 5 / CentOS 5 / Fedora Linux specific instructions here.

Install Open-iSCSI Initiator

Type the following command at a shell prompt:

$ sudo apt-get install open-iscsi

Open-iSCSI default configuration

You need to soft-link (path fix) few two files to autologin work i.e. fix file paths for iscsiadm, enter:

ln -s /etc/{iscsid.conf,initiatorname.iscsi} /etc/iscsi/

Default configuration file could be located at /etc/iscsi/iscsid.conf or ~/.iscsid.conf. Open /etc/iscsi/iscsid.conf file:

# vi /etc/iscsi/iscsid.conf

Set node.session.auth.username, node.session.auth.password and other parameter as follows:

node.startup = automaticnode.session.auth.username = MY-ISCSI-USERnode.session.auth.password = MY-ISCSI-PASSWORDdiscovery.sendtargets.auth.username = MY-ISCSI-USERdiscovery.sendtargets.auth.password = MY-ISCSI-PASSWORDnode.session.timeo.replacement_timeout = 120node.conn[0].timeo.login_timeout = 15node.conn[0].timeo.logout_timeout = 15node.conn[0].timeo.noop_out_interval = 10node.conn[0].timeo.noop_out_timeout = 15node.session.iscsi.InitialR2T = Nonode.session.iscsi.ImmediateData = Yesnode.session.iscsi.FirstBurstLength = 262144node.session.iscsi.MaxBurstLength = 16776192node.conn[0].iscsi.MaxRecvDataSegmentLength = 65536

Save and close the file. Restart open-iscsi service:

# /etc/init.d/open-iscsi restart

Now you need to run a discovery against the iscsi target host:

# iscsiadm -m discovery -t sendtargets -p ISCSI-SERVER-IP-ADDRESS

If 192.168.1.60 is iSCSI server IP address, enter:

# iscsiadm -m discovery -t sendtargets -p 192.168.1.60

OR

# iscsiadm --mode discovery --type sendtargets --portal 192.168.1.60

Note down the record id (such as iqn.2001-05.com.doe:test) found by the discovery. You need the same for login. Login, must use a node record id found by the discovery:

# iscsiadm --mode node --targetname iqn.2001-05.com.doe:test --portal 192.168.1.60:3260 --login

Finally restart the service again:

# /etc/init.d/open-iscsi restart

Format iSCSI Volume

Now you should see an additional drive on the system such as /dev/sdc. Use /var/log/messages file to find out device name:

# tail -f /var/log/messages

If your device name is /dev/sdc, enter the following command to create a partition:

# fdisk /dev/sdc

Next format partition:

# mkfs.ext3 /dev/sdc1

Mount file system:

# mkdir /iscsi# mount /dev/sdc1 /iscsi