Sharing block devices via iSCSI is a common way to make network-attached storage available. An iSCSI LUN is a logical unit of storage. In SoftNAS, the basic storage LUN is a volume that is accessed as a block device. The block device volumes have a mount point in the Linux /dev/zvol filesystem because they are disk block devices.
For example, a storage pool naspool1 with volume name lun01 would be named /dev/zvol/naspool1/lun01 as its mount point. These device references are links to Linux block devices used to access the volume's raw data blocks via iSCSI.
iSCSI targets are used by iSCSI initiators to establish a network connection. The target serves up the LUNs, which are collections of disk blocks accessed via the iSCSI protocol over the network. A target can offer one or more LUNs to the iSCSI clients, who initiate a connection with the iSCSI server.
For example, VMware or Windows connects to the iSCSI server and retrieves a list of available targets. Then, for each target, the list of its published LUNs are available for use.
1. Target Name Grid
The Target LUN Grid displays the list of targets and LUNs in a tabular grid format. It has the following fields.
Field | Description |
|---|---|
Target Name | It shows the complete path and name of the target. |
Delete Target | Link to delete target. |
2. Creating a Target
To do so, simply click the Create a Target option in the toolbar. The additional target will be created automatically, without additional steps.
3. Adding a LUN
You can create one or more volumes assigned as LUNs (iSCSI logical units) for each target. To do this, select the target, and click Add LUN, or double-click the desired target.
Either select the volume's block device from the dropdown (which will show available volumes).
Click Add LUN to link the block device to the iSCSI Target as a LUN.
Or check the box for Create a New Device, and enter the path, and the desired size to associate with the LUN.
Click Add LUN to link the block device to the iSCSI Target as a LUN.
Alternative Method - Double click to Add LUN
Instead of selecting the target and clicking Add LUN, you can simply double-click here, as it states. Follow the steps in #3 to finish adding your LUN.
4. Deleting a LUN/Target
You can now delete LUNs from a target, without deleting the target. An empty target can be deleted separately.
- To delete a LUN, select it from the list.
- Click the Delete link at the end of the Target Name Grid.
- The Delete Confirm message box asking you to confirm the deletion of the LUN will be displayed.
- Click the Yes button.
The selected LUN will be removed.
To delete a target, the same process is followed.
