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Setting up iSCSI (target/server and initiator/client) on RHEL

It's quite easy to setup an iSCSI environment on Red Hat Enterprise Linux. Try this easy setup to get a better understanding of iSCSI.

Ingredients:

  1. Two (virtual) machines, a server 172.16.0.1 and a client 172.16.0.2.
  2. Access to the "RHEL Cluster-Storage" channel on Red Hat Network.

N.B. SELinux must be disabled when using this recipe, iptables tcp port 3260 must be opened on the server.

On the server execute these commands to setup a 100 Mb iSCSI target. This target can later be mounted on the client(s).

# yum install scsi-target-utils
# cat /etc/tgt/targets.conf
<target iqn.2010-04.nl.meinit:node1.target1>
backing-store /iscsi1.img
initiator-address 172.16.0.2
</target>
# dd if=/dev/zero of=/iscsi1.img bs=1024 count=102400
# chkconfig tgtd on
# service tgtd start

Now on (all) client(s) follow these steps. (Please pay attention that only one client was give access in the configuration example above; 172.16.0.2.)

# yum install iscsi-initiator-utils

Start iscsi daemon.

# service iscsi start

To see what IQNs are available, run:

# iscsiadm -m discovery -t sendtargets -p 172.16.0.1

The result is a list of IQN(s) available. This discovery is a mandatory step of connecting to the iSCSI target.

Login to the iSCSI target:

# iscsiadm -m node -T iqn.2010-04.nl.meinit:node1.target1 -p 172.16.0.1 -l

If that all works, you have new SCSI devices available, check dmesg and start iscsi at boot time:

# chkconfig iscsi on

In this example the iSCSI target does not have a filesystem. Create it on the client and mount it at boot time:

# fdisk /dev/sda
# mkfs.ext3 /dev/sda1
# echo "/dev/sda1 /mnt ext3 defaults,_netdev 0 0" >> /etc/fstab

You are done, but these commands are quite useful when connecting to an unknown iSCSI device.

To see more about the IQN:

# iscsiadm -m node -T iqn.2010-04.nl.meinit:node1.target1 -p 172.16.0.1

Comments

Wed, 05/18/2011 - 08:28 — dim (not verified)

It can be very useful, not

It can be very useful, not only the obvious point that the deposit will not need to adapt to the computer. iSCSI you can put on the best place to store sheets, which are noisy and put out a lot of heat, try to quiet PC with a lot of internal disks will always be the exercise in futility. Much better to put them on the plates to another location, such as a garage, and keep the noise and heat your home.
alex
Blackjack Players

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