This article will show you how to configure Open-iSCSI initiator (client) to connect to an existing iSCSI target (server). I will not actually review how to setup the iSCSI Target in this article. If you don’t already have an iSCSI Target available in your environent, you might take a look at OpenFiler.
In this guide, I am using a CentOS 6.5 system as the iSCSI initiator (client) and will connect to an existing iSCSI target.
Install the Open-iSCSI software
On my CentOS 6.5 system, the Open-iSCSI package is not installed by default. You can check to see if your system has the package installed by running the following command:
[root@linux ~]# rpm -qa | grep iscsi-initiator-utils
If the iscsi-initiator-utils package is not already installed, use the “yum” command to install it:
[root@linux ~]# yum install iscsi-initiator-utils
Start the iSCSI service
After installing the iscsi-initiator-utils packs, start the iscsid service and configure both the iscsid and iscsi services to automatically start each time the system boots:
[root@linux ~]# /etc/init.d/iscsid start
[root@linux ~]# chkconfig iscsid on
[root@linux ~]# chkconfig iscsi on
Discover iSCSI Targets
Use the iscsiadm command to discover all of the iSCSI targets on your iSCSI Target server (i.e. your iSCSI SAN. In this case my server running OpenFiler):
[root@linux ~]# iscsiadm -m discovery -t sendtargets -p 192.168.197.201
192.168.197.201:3260,1 iqn.2006-01.com.openfiler:tsn.target1
Note: In my example, the hostname of my iSCSI Target (SAN) is “openfiler.mydomain.com” and has an IP address of 192.168.197.201
Login to the iSCSI Target and configure automatic login at boot time
[root@linux ~]# iscsiadm -m node -T iqn.2006-01.com.openfiler:tsn.target1 -p 192.168.197.201 --login
[root@linux ~]# iscsiadm -m node -T iqn.2006-01.com.openfiler:tsn.target1 -p 192.168.197.201 --op update -n node.startup -v automatic
Verify iSCSI session is active
[root@linux ~]# iscsiadm -m session
tcp: [1] 192.168.197.201:3260,1 iqn.2006-01.com.openfiler:tsn.target1
Identify which device the iSCSI target maps to
[root@linux ~]# (cd /dev/disk/by-path; ls -l *iscsi* | awk '{FS=" "; print $9 " " $10 " " $11}')
ip-192.168.197.201:3260-iscsi-iqn.2006-01.com.openfiler:tsn.target1-lun-0 -> ../../sdc
This tells us that the iSCSI target has been mapped to /dev/sdc on the system. From here, use standard partitioning/formatting commands (fdisk, mkfs, etc) to setup the disk as desired!