UFS Growing Disks

TobiasW · Aug 15, 2020

Hello everybody,

I tried to grow a UFS Partition inside a virtualbox VM (.vhd disk format).

I went trough https://www.freebsd.org/doc/handbook/disks-growing.html and everything was fine until

Code:

growfs /dev/ada1p3
Operation not permitted

occurred.

I googled a bit around and found following thread

FreeBSD growfs: operation not permitted (aka: enlarge your partition) | DigitalOcean

Hi there, I recently upgrade my Droplet from 20 to 30 GiB space, yet I’m unable to resize my filesystem space in order to fill the new hard disk size. I h…

www.digitalocean.com

and noticed that
growfs /dev/gpt/rootfs
worked smoothly.

Is this intended? Might it be a good idea to add a note to the documentation?

Best,
Tobias

George · Aug 16, 2020

You can file a PR (patch), and suggest a change in that section of the handbook.

There is a bug report on this already PR 237392. Maybe Post there.

bugzeo · Jan 7, 2023

I have the same problem here:

UFS - How to resize the root partition after enlarging the hard disk?

I have a virtual machine with FreeBSD inside Virtualbox, the disk is 20GB let's say, and want to enlarge it to 50GB. With Virtualbox tools I just enlarge the disk no problem, but how do I do to resize the root filesystem, which is a freebsd-ufs type at /dev/ada0p4 device?

forums.freebsd.org

Maybe is that you should not be able to use growfs on mounted filesystems?

tingo · Jan 8, 2023

The growfs(8) man page says that you should be able to resize mounted filesystems (well, from FreeBSD version 10 at least).

bugzeo · Jan 8, 2023

tingo said:
The growfs(8) man page says that you should be able to resize mounted filesystems (well, from FreeBSD version 10 at least).

Thanks a lot! Let's see if some update fixes it.

Alain De Vos · Jan 8, 2023

A (simple alternative is):
- Backup ,delete-partition , recreate-partition, copy-over.

bugzeo · Jan 8, 2023

Alain De Vos said:
A (simple alternative is):
- Backup ,delete-partition , recreate-partition, copy-over.

The idea is to do it from live / system. If I'm to destroy my root I just reboot to live cd and do it from there, since it works.

darkfader · Aug 31, 2025

bugzeo said:
I have the same problem here:

UFS - How to resize the root partition after enlarging the hard disk?

I have a virtual machine with FreeBSD inside Virtualbox, the disk is 20GB let's say, and want to enlarge it to 50GB. With Virtualbox tools I just enlarge the disk no problem, but how do I do to resize the root filesystem, which is a freebsd-ufs type at /dev/ada0p4 device?

forums.freebsd.org

Maybe is that you should not be able to use growfs on mounted filesystems?

generally, even if it's gravedigging:
why not, it has been possible in most filesystems since like late 90s/early 2000. With that in mind, it would be better to declare any problems around live (not livecd as in offline) resize "a not yet implemented" rather than a y"ou should not do this". (Even filesystem shrink worked on better FS no later than 2005ish, usually didn't survive the Linux porting for whatever reasons)

from a filesystem tool point of view, you absolutely want to support online resize since whatever changes one needs to make it work reliably, non-data-shredding are cases that remove prior unaddressed edge cases that just weren't possible to hit before, IOW it exposes bugs or design oversights. That's the best thing to happen for a filesystem.