Scope/Description

This guide details the process of creating a new iSCSI lun and adding it to the configuration. Replace variables in the example comamnds defined with curly braces with the correct name, i.e. {pool_name } -> pool1.

Prerequisites

• ZFS Storage pool configured
• iSCSI configured

Steps

Create a Block Image for the iSCSI Lun

• Create a sparse image file before using targetcli. This will create the image, specify the lun name and size. By default 45Drives stores lun images at /{pool_name}/images

cd /{pool_name}/images
dd if=/dev/zero of={lun_name} bs=1 count=0 seek=(size of LUN)

• See example commands below.

[root@av15-rocky45d images]# cd /tank_mirror/images
[root@av15-rocky45d images]# dd if=/dev/zero of=testlun bs=1 count=0 seek=1T
0+0 records in
0+0 records out
0 bytes copied, 9.8113e-05 s, 0.0 kB/s

Entering Targetcli Config

• To make changes to the targetcli configuration, run the following command.

targetcli

Creating Fileio Storage Object

• Create a fileio storage object, using the created lun in the previous steps.

/> cd backstores/fileio
/backstores/fileio> create {lun_name} /{pool_name}/images/{lun_name}

• Example below:

/backstores/fileio> create testlun /tank_mirror/images/testlun
Created fileio testlun with size 1099511627776

• Verify your block devices have been created in targetcli

/backstores/fileio> ls
o- fileio ..................................................................................................... [Storage Objects: 1]
  o- testlun ...................................................................... [/tank_mirror/images/testlun (1.0TiB) write-back deactivated]
    o- alua ....................................................................................................... [ALUA Groups: 1]
      o- default_tg_pt_gp ........................................................................... [ALUA state: Active/optimized]

Adding new Lun to Existing iSCSI Target

• Change the targetcli working directory to the iSCSI target’s lun directory, then add the lun to the existing target.

cd /iscsi/{target_name}/tpg1/luns/
create /backstores/fileio/{lun_name}

• Example below:

/> cd /iscsi/iqn.2023-02.labtest:test.environment/tpg1/luns/
/iscsi/iqn.20...ent/tpg1/luns> create /backstores/fileio/testlun 
Created LUN 2.
Created LUN 2->2 mapping in node ACL iqn.1991-05.com.microsoft:win-9171j57n62e
Created LUN 2->2 mapping in node ACL iqn.1991-05.com.microsoft:win-clvclj26v2c

• The output will show the new lun being mapped to each of the clients iqns that correspond to the iSCSI target.

Exit and Save Configuration

• Exit the configuration, this is required for changes to take affect. A backup file will be written to /etc/target/saveconfig.json on RHEL based distros, and /etc/rtslib-fb-target/saveconfig.json

/iscsi/iqn.20...ent/tpg1/luns> exit
Global pref auto_save_on_exit=true
Last 10 configs saved in /etc/target/backup/.
Configuration saved to /etc/target/saveconfig.json

Verification

• Open “iSCSI Initiator”
• Enter Target IP into “Target” field
• Hit quick-connect