FreeNAS was renamed to TrueNAS Core in October 2020.

What is FreeNAS and why would I want to use it?

FreeNAS is a free operating system (OS) with software built specifically to be a storage server. The underlying OS is FreeBSD Unix, but down’t let that scare you off. You don’t need to know Unix or Linux to use FreeNAS. You just need some basic computer and networking knowledge.

One of the best features of FreeNAS is that it uses ZFS and it’s rich set of features. Again, you don’t have to know ZFS management to use this. However, the features of ZFS will help you manage your data without any data loss. I will not describe all of the ZFS features as that’s out of the scope of this article; but I will describe a few that will most likely benefit you.

First, ZFS will manage your hard drives and RAID configuration. Therefore, you should NOT setup any RAID configuration in your computer. You want to have FreeNAS/ZFS see the disks directly. If you have already purchased your computer and don’t have a choice and are required to setup a RAID set, then some people will create individual RAID 0 (Stripe, no redundancy) sets for each disk. This is not ideal, but will work to some degree. You won’t see the drive health and you won’t get the full disk size available to you.

For more information about ZFS RAID pools, I recommend you read this JRS Systems blog article.

Second, is the ability to create snapshots. Snapshots are backup copies of your files. This means that if you delete or modify files in a way that you are not happy with the result, you can recover the older version of the file(s) from the snapshot as long as a snapshot has been created from before the change and was kept.

You don’t necessarily have to build a new pool to increase the size. You can actually OFFLINE 1 disk from the pool and replace it with a larger disk, then let it resilver (rebuild the data). Once the resilver is complete, then you OFFLINE the next drive and replace it. You keep this process going until all of the drives are replaced. Then your pool size will automatically be increased. REMEMBER to only replace 1 at a time after the resilver process is completed.

Since we’re talking about storage here, we definitely need to talk about the system hardware. Fortunately, FreeBSD, and therefore, FreeNAS has modest hardware requirements. Most PCs that run Windows will work. However, a storage server will need lots of hard drive space to store your files. How much space will be determined by how much you need to store. You will also need to have a computer system that can handle enough hard drives to cover the redundancy you want. This is where the computer knowledge comes in handy. If you are using an average PC for data backup, then you might want only 2 drives in a Mirror configuration or for data storage you will want at least 3 drives in a raidZ (a.k.a. raidZ1). Although, there are articles that state that RAID5/raidZ1 is not recommended in favor of RAID6/raidZ2.

In my case, I have a LOT have data that I will be storing. Therefore, I purchased a refurbished enterprise grade server on eBay. I have a 4U Supermicro 24 bay server. This means that it can hold up to 24 hard drives for data.

Installation is easier that you might thing. The recommended process is to use a USB thumb drive at least 8GB in size. This may sound strange, but this leaves all hard drives to store data.

Read the installation instructions:

FreeNAS 9.10: https://doc.freenas.org/9.10/install.html

There is also a new version (10) Corral available. The web interface is dramatically different. I like the new interface, but there are some caveats. For example, the new interface uses a graphical drag-and-drop interface to create your pool of disks. If you’re not very careful, you could end up with 1 disk not in the raidz that you wanted, but instead as another vdev in the pool. That means that if the vdev with 1 disk fails, the entire pool will fail and lose your data. Supposedly there are safeguards being added to the next releases, but for now, you MUST pay attention to your pool design and failed disk replacement.

* UPDATE *
Version 10 (Corral) has been abandoned. Instead, install version 11.3.