Well its not a big deal to add a drive because they are not going to rewrite the fstab on the system when they update the docker container apps. Even the OS underneath (Debian 12)
fstab is used to define what drives are associated to a path and os paths assigned to alternate paths for program level.
on a normal Linux install you generally have a boot and root partition and maybe a swap one so the fstab looks something like this:
in above you see the phsyical drives (as UUID partitions, one is the boot and one is the root) and a swap file directory defined
A lot of people don’t use mounting a directory as a system path often in linux programming and assign the docker container system paths which does look confusing:
# entries kept from original fstab
# <device> <dir> <type> <options> <dump> <fsck>
/ /mnt/root none bind 0 0
/data/umbrel-os/var/log /var/log none bind 0 0
/data/umbrel-os/var/lib/docker /var/lib/docker none bind 0 0
/data/umbrel-os/home /home none bind 0 0
/data/umbrel-os/var/lib/systemd/timesync /var/lib/systemd/timesync none bind 0 0
But they do this so programs install user data in the correct path as well as the system program in the correct paths. from the docker container’s web gui.
in linux the /home directory is where the user’s files are created.
programs or log install in various (/var) and optional (/opt) while plugins and shared objects install in user share (/usr) shared command in shared binaries (/sbin) and os binaries are in binaries (/bin) and config files are stored in os extensions (/ect) directory.
UmbrelOS is docker container in the /data directory it installs on a Debian headless or known today as a server os instance (without a native gui).
So there are a few of ways you can expand into a different drive.
But say I wanted to move my bitcoin node to be installed on a different drive. it installs itself in /home/user/.bitcoind directory so I move my /home onto a different drive.
I would format my drive at the terminal then copy the contents of /data/umbrel-os/home or /home to it which is the same directory.
add the drive mount entry and mount it as /home
then put a # symbol at the beginning of the line to comment the line and keep the setting in case you want to revert to the old home again.
The way the link describes how to use fstab is technically incorrect because you want to use that partition universal unix identifier (UUID) instead of the device mount path (/dev/sd* or /dev/nmve*) because if the drives are moved around from one SATA port to another, or you move a m.2 drive to a different slot, they are on different device path than what was declared in fstab and it will fail to mount and it will fail booting (most linux distributions will stop booting so you can fix this in the recovery console)
I can post what I did to make my /home on a 2TB dive on my umbrel that I installed on my m.2 SSD in more detail if you need that even though its the same affair as other linux guides. Because you copy the /home directory.
After I successfully have transfer the /home mount to a drive I delete the contents of /data/umbrel-os/home since its on the new drive and free up space for other programs to be installed
