Leonardo's blog: FreeBsd resize VirtualBox disk

I have a FreeBsd 9.1 VirtualBox guest machine I've created with a 10G disk. After installing my usual programs, I've got the not-so-friendly "disk full" message.

What to do:

Resize the virtual disk:

VBoxManage \
  modifyhd "FULL_PATH_TO_VDI" \
  --resize SIZE_IN_MBS

For example:

VBoxManage modifyhd "/home/leonardo/VMS/FreeBsd91/disk.vdi" --resize 20480

This will resize the disk up to 20Gb

Let the system know you have resized the disk:

Boot in single user mode and follow these steps:

# gpart show
=>  34  21942973 md0 GPT          (CORRUPTED)
    34       256   1 freebsd-boot (64k)
   290  21943129   2 freebsd-ufs (10G)

The first thing to note is the "CORRUPTED" label. To fix it just do:

# gpart recover ada0

Now, it's time to grow the 10G partition to fill the whole 20G disk:

# gpart resize -i 2 ada0
gpart: Device busy

If you get the "Device busy" message:

# sysctl kern.geom.debugflags=16
kern.geom.debugflags: 0 -> 16
# gpart resize -i 2 ada0
gpart resized

Ok, now the partition was resized. The last step is to resize de filesystem on it:

# growfs /dev/ada0p2

Done!, now reboot and enjoy your big disk!.

EDIT: Today I've received a comment on Google Plus by Edward Tomasz Napierała about improvements on FreeBsd 10. Here's the comment:

Note that in 10-CURRENT it's possible to do all this without going single-user.
The 'debugflags' step is also not required.
In 9-STABLE it's possible to resize the filesystem mounted read-write,
but it's not possible to resize the partition.