One of my favorite parts about UnRaid is the seamless ability to create virtual machines. I like to do most of my work on Linux and having a VM allows me to try different distros and easily manage resource use. In order to easily do this, though, I need to have my /home directory persist across multiple installs. To manage this, I create a share on UnRaid which is then mounted at boot as my home directory within a VM. Here is my process.

Move your `home` directory to a share

Assuming you have already created an UnRaid user share where you’re going to store your home directory (and I highly recommend using your cache drive for this share), you need to first move any files on your linux install to the server. If you’re installing linux for the first time (ie. nothing important exists in your home directory, you can skip this step).

First, we’ll create a temporary mounting point for the share (make sure the cifs-utils package is installed. With a Debian-based distro you can use the command sudo apt-get install cifs-utils). We’ll assume the username is john and the share you created is called john_home.

sudo mkdir /mnt/tmp
sudo mount -t cifs -o guest //servername/john_home /mnt/tmp

If you get an error with the previous command, you can use your server’s IP address in place of servername or edit your /etc/hosts file. I prefer doing the latter, and all you need to do is add an entry to /etc/hosts with the format <ip address> <name> (editing the file with sudo). So if my server was called servername and had an IP address of 192.168.0.77 I’d add the following to /etc/hosts:
192.168.0.77   servername
Now you can re-run the previous mount command

We can then copy our home directory over to this temporary mount point and, once it completes, ensure that our files are actually there.

sudo rsync -avx /home/john /mnt/tmp
ls -lah /mnt/tmp

Finally, we can unmount the share with

sudo umount /mnt/tmp

Before we permanently mount a share as our home directory, we should back up our current home and test it out. We’ll first move our home directoy to a backup location and then mount the share as our home and verify everything is there and working.

sudo mv /home/john /home/john_bak
sudo mkdir /home/john
sudo mount -t cifs -o guest,uid=$(id -u),gid=$(id -g),mfsymlinks //servername/john_home /home/john
ls -lah /home/john

Assuming everything is working properly, we can move on to editing the fstab entry to make this change permanent.

Note: if you have any git repos in your home directory, you’ll want to push any changes in them to a remote repo prior to performing the next step. In my experience, the git history gets all messed up and thinks the existing files are all new. I just pushed any changed to a github branch and then re-cloned after I was finished.

Finally we can permanently make the unraid share our linux home by editing fstab. Use whatever editor you like (I prefer vim to make the change as sudo):

sudo vim /etc/fstab

And then append the following line:

//servername/john_home  /home/john  cifs  guest,uid=john,gid=john,mfsymlinks   0   0

You can now restart your VM and you home directory should automatically mount.

Future linux installs

If you ever want to install a new VM, you can use the following commands to quickly map your home directory without performing any tests in the future:

sudo vim /etc/hosts
  # Inside /etc/hosts
  <ip-address>  servername
sudo apt-get install cifs-utils
sudo mv /home/username /home/username_bak
sudo vim /etc/fstab
  # Inside /etc/fstab
  //servername/usershare /home/username  cifs  guest,uid=username,gid-username,mfsymlinks  0 0
sudo reboot

Why bother?

One major reason I want to do this is so I can minimize the vdisk size for my VMs since a bulk of space is spent in my home directory. This way I can use as much space as I want AND back my home directory up with a tool like Duplicati. It also allows me to easily migrate between different linux distros, which is nice.

Anyways, I hope this helped someone else out there!