Can I uninstall ZFS if using ext4 for everything?

Question

I have never used ZFS for anything (that I know of).

To my surprise, there are 4 packages installed by default on my new installation of Linux Mint 22 (Cinnamon).

Naturally my question is, if I can uninstall all ZFS-related packages if using ext4 for everything? Safely I mean, if it is not used by any means internally. And if I can, how exactly to proceed?

Answer 1

First, run this to find if you actually have some ZFS-related packages installed:

$ dpkg -l | grep -i zfs 

Second, simulate the removal of libzfs4linux, this one includes not all, but some ZFS packages.

$ sudo apt-get --simulate purge libzfs4linux 

---

In my case, I found 4 ZFS packages, and 3 of them would have been removed, one missing was libzpool5linux.

So, I ended up running:

$ sudo apt-get purge libzfs4linux libzpool5linux 

There did not seem to be any changes needed afterward.

Good luck, and backup everything as always before such a change.

Answer 2

I also have Mint 22 with Cinnamon and ext4. I tried several commands:

ps -ef | grep zfs 

showed no ZFS processes running

systemd-analyze blame | grep zfs 

showed four services that ran briefly during boot-up:

2.123s zfs-load-module.service

18ms zfs-share.service

15ms zfs-volume-wait.service

6ms zfs-mount.service 

All of these services exited normally, as shown by

systemctl status zfs-load-module.service 

and ditto for the other services.

It seems to me (as a complete non-expert in boot internals) that they were simply looking for ZFS volumes to mount, then stopped when there were none.

If you REALLY want to save a couple of seconds of boot time (probably less in clock time if your system runs services in parallel), then simply disable these services.

sudo systemctl disable <service name> 

Disabling a service is much less dangerous than uninstalling a package, although there is still a risk that you end up with a system that will not boot. I cannot quantify the risk, so you proceed at your own risk. MAKE SURE YOU BACK UP ALL YOUR DATA AND ANY CHANGED CONFIGURATION FILES. If you are worried, have a live boot USB handy, Mint is easy enough to re-install.