CentOS 8.x iSCSI target server setup

<yambe:breadcrumb self="iSCSI target server setup">CentOS 8.x iSCSI|iSCSI</yambe:breadcrumb>

CentOS 8.x iSCSI target server setup

To setup CentOS 8.x machine for iSCSI target use:

1. Create appropriate file-system and mount it at desired location (eg /backstores) to be used for storing iSCSI disk images (parted, mkfs.ext4, /etc/fstab, mount -a, df -h, etc.)
2. Install targetcli package using:

   dnf -y install epel-release
   dnf -y install targetcli

3. Clear existing configuration (if any) using:

   targetcli clearconfig confirm=true

4. Go to /backstores in OS and create desired backing store using:

   cd /backstores
   qemu-img create -f raw primary.iscsi 800G

   where primary.iscsi is name of iSCSI backing store file and 800G is its size

5. Run targetcli and configure it using:

   #Create file to be used as iscsi backstore
   cd /backstores/fileio
   create primary /backstores/primary.iscsi
   cd ..
   ls
   #Note that we can also use block devices using /backstores/block
   
   cd /iscsi
   #This will create IQN number automatically
   #Ideally we should create different iqn numbers for every backstore
   #So that there is flexibility on client side.  We can run
   #create multiple times to create different iqn numbers.
   create
   cd iqn.<press-tab-to-autocomplete>
   
   
   #Create lun
   cd tpg1/luns
   create /backstores/fileio/primary
   
   #Allow client IQN numbers without authentication
   cd ../acls
   create <client1-iscsi-initiator-name>
   create <client2-iscsi-initiator-name>
   
   #Save and exit
   cd /
   saveconfig
   exit

   Client initiator name is located in file '/etc/iscsi/initiatorname.iscsi'. Take only value after 'InitiatorName=' starting with 'iqn.'

6. Configure service to start on system boot and also start it for current run:

   systemctl enable target
   systemctl start target

7. Disable firewall or given exception for port 3260

   systemctl disable firewalld
   systemctl stop firewalld

<yambe:breadcrumb self="iSCSI target server setup">CentOS 8.x iSCSI|iSCSI</yambe:breadcrumb>