Chapter 27. Set up an iSCSI Target and Initiator

Procedure 27.1. Create an iSCSI Target

1. Install scsi-target-utils.

   ~]# yum install scsi-target-utils

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2. Open port 3260 in the firewall.

   ~]# iptables -I INPUT -p tcp -m tcp --dport 3260 -j ACCEPT
   ~]# service iptables save
   

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3. Start and enable the target service.

   ~]# service tgtd start
   ~]# chkconfig tgtd on
   

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4. Allocate storage for the LUNs. In this example a new partition is being created for block storage.

   ~]# fdisk /dev/vdb
   Welcome to fdisk (util-linux 2.23.2).
   
   Changes will remain in memory only, until you decide to write them.
   Be careful before using the write command.
   
   Device does not contain a recognized partition table
   Building a new DOS disklabel with disk identifier 0x43eb8efd.
   
   Command (m for help): n
   Partition type:
      p   primary (0 primary, 0 extended, 4 free)
      e   extended
   Select (default p): *Enter*
   Using default response p
   Partition number (1-4, default 1): *Enter*
   First sector (2048-2097151, default 2048): *Enter*
   Using default value 2048
   Last sector, +sectors or +size{K,M,G} (2048-2097151, default 2097151): +250M
   Partition 1 of type Linux and of size 250 MiB is set
   
   Command (m for help): w
   The partition table has been altered!
   
   Calling ioctl() to re-read partition table.
   Syncing disks.
   

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5. Edit the /etc/tgt/targets.conf file to create the target.

   ~]# cat /etc/tgt/targets.conf
   ...
   default-driver iscsi
   <target iqn.2015-06.com.example.test:target1>
   	backing-store /dev/vdb1
   	initiator-address 10.10.1.1
   </target>
   

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   In the above example a simple target containing one backing store and one allowed initiator has been created. It must be named with an iqn name in the format of iqn.YYYY-MM.reverse.domain.name:OptionalIdentifier. The backing store is the device the storage is located on. The initiator-address is the IP address of the initiator to access the storage.
6. Restart the target service.

   ~]# service tgtd restart
   Stopping SCSI target daemon:     [ OK ]
   Starting SCSI target daemon:     [ OK ]
   

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7. Check the configuration.

   ~]# tgt-admin --show
   Target 1: iqn.2015.06.com.example.test: server
   	System information:
   		Driver: iscsi
   		State: ready
   	I_T nexus information:
   	LUN information:
   		Lun: 0
   			Type: controller
   			SCSI ID: IET    00010000
   			SCSI SN: beaf10
   			Size: 0 MB, Block size: 1
   			Online: Yes 
   			Removable media: No
   			Prevent removal: No
   			Readonly: No
   			Backing store type: null
   			Backing store path: None
   			Backing store flags:
   		LUN: 1
   			Type: disk
   			SCSI ID: IET     00010001
   			SCSI SN: beaf11
   			Size: 2147 MB, Block size: 512
   			Online: Yes
   			Removable media: No
   			Prevent removal: No
   			Readonly: No
   			Backing store type: rdwr
   			Backing store path: /dev/vdb1
   			Backing store flags:
   	Account information:
   	ACL information:
   		10.10.1.1
   

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