How to Create a New Jail in TrueNAS 12.0

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TrueNAS offers many possibilities for the users to install applications on top of the TrueNAS system. There are two ways to install applications in TrueNAS. The first way is using the Plugins menu. Here we can select the application offered by the built-in IXSystem or via Community. There are not many applications we can choose from here. It’s pretty limited. The second way is to install the application manually using the Jail. I would recommend you to read more about Jail using the following link.

So in this article, I am going to create a new Jail. Jail is more like a FreeBSD virtual machine, but it’s not a true virtual machine. We cannot define the amount of RAM and other resources to the jail. To install applications such as WordPress or Nextcloud, TrueNAS will need to create jail for each of them. Read more about TrueNAS Jail.

The differences between Jail and Virtual Machines

You may wonder what are the differences between Jail and Virtual Machines in TrueNAS. Both type of virtualization is supported by TrueNAS. The main difference between the two is that the Jail uses FreeBSD operating system. On the other side, we can put or install almost any operating system into Virtual Machines.

The Virtual Machine has more options in terms of OS choice, the hardware resources we assigned to the VMs which is very limited on the Jail side. So we will have full features of the OS that we installed on the virtual machine.

On the other hand, the Jail offers an isolated system from the host/server. It only supports FreeBSD and there are no options for resource allocation such as how much RAM we want to assign to the Jails. Jail is great for a single application. For example, we want to build a web server only, then Jail is a good choice rather than using the VM. IMHO.

How to Create a New Jail

Now let’s take a look at how to create a new Jail. I am using the latest version of TrueNAS 12.0 for this tutorial.

  1. Login to TrueNAS dashboard
  2. Go to Jails
  3. Make sure you have configured the pool storage for TrueNAS Plugins and Jails
  4. Click Add button
  5. Give a name for the new jail
  6. Choose the version from the list
  7. Configure the Network. You can choose DHCP, NAT or even manual IP address
  8. Click Submit

The following video will show you how to create a new Jail in TrueNAS

Once finished, you can start the Jail immediately. But please note that this new Jail has no access to the host storage. We can further modify our Jail to be able to access our storage using the Mount Point option.

How to create a mount point

To create a new mount point, first shut down the Jail. And then go to Mount Point. From there, we can add new mount points as needed.

In some cases, you will need to edit the ACL. Otherwise, the mount point is owned by root user.