If you aren’t a system administrator maybe you don’t know what iSCSI is. It’s a network protocol that let you send SCSI commands to a host machine. The purpose? Simple, it let you use a NAS (or a SAN) as an internal drive.
iSCSI wasn’t created to connect network drives but to virtualize storage. It’s possible to deploy multiple LUNs (Logic Unit Number, de facto a virtual disk) on a single target and connect them to multiple computers. Access credentials may be configured for security purposes.
Furthermore, every LUN can be partitioned with any file system, making them a full supported drive for Windows, Mac OS, Linux and Unix operating systems. Now you can look at the big picture and understand how powerful iSCSI is: a perfect tool for virtualization but a highly valuable one even for common users.
Setting up an iSCSI target it isn’t a trivial operation even for geeks. Given the possibilities offered by this protocol, I wanted to create a tutorial. Most of SOHO NAS doesn’t support iSCSI. For this guide I used a cheap QNAP TS-412, a four bay, Marvell-based, network attached storage that features two Gigabit ethernet. It wouldn’t be difficult to adapt the tutorial to other NAS, especially if you consider that only the iSCSI target and the LUN have to be configured on the device. The rest of the setup must be made on your PC.
So let’s see how to get the job done!
The first step is to enable the iSCSI target on the NAS web interface. Access to your NAS and navigate to the iSCSI page.
Select Enable iSCSI Target Service and click on Apply.
Open the Target Management tab and start the Quick Configuration Wizard.
A window like the one below will appear. We want to create both a target and a LUN so click on the related button.
A reminder will be shown. Click next.
Specify the name and the alias (de facto a simplified name of the target).
If you are setting up several iSCSI targets for a business or an istitutional network you probably want to configure access credentials. For iSCSI this means a CHAP authentication. In SOHO environments this kind of protection is rarely required so we’ll skip this step. Click on next.
Now it’s time to configure the LUN. First of all, set the LUN allocation field on thin provisioning: this means that only the used space of the LUN will be allocated on the physical volume (of the NAS). It’s a disk space optimization. Specify the LUN name and the capacity.
Proceed to the next two windows and the setup is finished.