How to increase a proxmox VM disk and have opnsense/freebsd expand a UFS file system

[del13r]

This old topic helped me out: https://forum.opnsense.org/index.php?topic=19250
I thought I would create a new topic here for me to refer to in future and to help anyone else out in the same position.

I have opnsense running on proxmox. Setup is rock solid, no complaints.
I found that Zenarmor was consuming more disk space once I got a faster internet connection.
This prompted me to increase the disk space on my opensense VM.

Here is how I did it.

Find the disk of your VM on proxmox.

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Step 1, resize the proxmox virtual disk on Proxmox/Debian (VM Host)

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ssh root@proxmox

root@proxmox:~# qm resize 100 scsi1 +120G
  Size of logical volume pve/vm-100-disk-1 changed from 30.00 GiB (7680 extents) to 150.00 GiB (38400 extents).
  Logical volume pve/vm-100-disk-1 successfully resized.

# originally wanted 150G but later decided i wanted 200G

root@proxmox:~# qm resize 100 scsi1 +50G
  Size of logical volume pve/vm-100-disk-1 changed from 150.00 GiB (38400 extents) to 200.00 GiB (51200 extents).
  Logical volume pve/vm-100-disk-1 successfully resized.

# checking size of the VM disk after resize

root@proxmox:~# fdisk /dev/mapper/pve-vm--100--disk--1 -l
Disk /dev/mapper/pve-vm--100--disk--1: 200 GiB, 214748364800 bytes, 419430400 sectors

Device                                  Start       End   Sectors   Size Type
/dev/mapper/pve-vm--100--disk--1-part1     40    532519    532480   260M EFI System
/dev/mapper/pve-vm--100--disk--1-part2 532520    533543      1024   512K FreeBSD boot
/dev/mapper/pve-vm--100--disk--1-part3 533544 419430359 418896816 199.7G FreeBSD UFS

Step 2, resize and then grow the file system on Opnsense/FreeBSD (VM Guest)

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ssh root@OPNsense

root@OPNsense:~ # gpart show
=>      40  419430320  da0  GPT  (200G)
        40    532480    1  efi  (260M)
    532520      1024    2  freebsd-boot  (512K)
    533544  62380976    3  freebsd-ufs  (30G)
  62914520  356515840      - free -  (170G)

root@OPNsense:~ # gpart resize -i 3 da0
da0p3 resized

root@OPNsense:~ # gpart show
=>       40  419430320  da0  GPT  (200G)
         40     532480    1  efi  (260M)
     532520       1024    2  freebsd-boot  (512K)
     533544  418896816    3  freebsd-ufs  (200G)

root@OPNsense:~ # df -h
Filesystem                  Size    Used  Avail Capacity  Mounted on
/dev/gpt/rootfs              29G    12G    15G    44%    /

root@OPNsense:~ # growfs /
Device is mounted read-write; resizing will result in temporary write suspension for /.
It's strongly recommended to make a backup before growing the file system.
OK to grow filesystem on /dev/gpt/rootfs, mounted on /, from 30GB to 200GB? [yes/no] yes

root@OPNsense:~ # df -h
Filesystem                  Size    Used  Avail Capacity  Mounted on
/dev/gpt/rootfs              193G    12G    166G    7%    /



[meyergru]

You should change the title to include "with an UFS install" - I think you need different (probably no steps at all) inside the VM for ZFS installs.

[Patrick M. Hausen]

I think you need different (probably no steps at all) inside the VM for ZFS installs.

The GPT partition resizing is exactly the same. After that I am not quite sure from the top of my head if the vdev is expanded automatically today or if you still need "zpool online -e <pool> <partition>".

I just wonder why @del13r's instructions do not show gpart complaining about the missing backup partition table and the necessity to run "gpart recover" before "gpart resize".

[Maurice]

OPNsense does the partition and file system adjustments automatically, for both UFS and ZFS. You trigger this by creating a "magic file":

• touch /.probe.for.growfs
• Shutdown OPNsense and expand the disk image (qemu-img resize / Resize-VHD / qm resize / ...)
• There is no step 3. When OPNsense boots, the rc script performs its magic.

Cheers
Maurice

[Patrick M. Hausen]

Wow! 🤯

[del13r]

You should change the title to include "with an UFS install" - I think you need different (probably no steps at all) inside the VM for ZFS installs.

Thanks, I have updated the title to specify UFS file system.

[del13r]

Shutdown OPNsense

Thanks for the tip.
When I did my steps above, I did not have to shutdown or restart opnsense.

[Maurice]

@del13r Good point. If uptime is critical, the manual approach might be worth it.

Cheers
Maurice

[nero355]

I am not quite sure from the top of my head if the vdev is expanded automatically today or if you still need "zpool online -e <pool> <partition>".

When you are talking about a regular ZFS NAS setup with let's say 5 HDD's and RADIZ2 configured and then replace all 5 of them with larger HDD's then ZFS will automatically expand the VDEV for some years now :)

OPNsense does the partition and file system adjustments automatically, for both UFS and ZFS. You trigger this by creating a "magic file":

• touch /.probe.for.growfs
• Shutdown OPNsense and expand the disk image (qemu-img resize / Resize-VHD / qm resize / ...)
• There is no step 3. When OPNsense boots, the rc script performs its magic.

So the file you create with the touch command has the special name that triggers the expansion ?

[Maurice]

So the file you create with the touch command has the special name that triggers the expansion ?

Correct. The rc script checks whether this file exists. If it does, the partition and file systems modifications are executed and the file is deleted, so this happens only once:

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GROWFS_MARKER=/.probe.for.growfs
[...]
if [ -f ${GROWFS_MARKER} ]; then
    if [ -n "${ROOT_IS_UFS}" ]; then
        grow_partition ${ROOT_IS_UFS}
        growfs -y "/"
    elif [ -n "${ROOT_IS_ZFS}" ]; then
        zpool list -Hv ${ROOT_IS_ZFS} | while read NAME MORE; do
            if [ "${NAME}" != "${ROOT_IS_ZFS}" ]; then
                grow_partition ${NAME}
                zpool online -e ${ROOT_IS_ZFS} ${NAME}
            fi
        done
    fi
fi
[...]
rm -f ${GROWFS_MARKER}

/.probe.for.growfs exists on nano, vm and arm images so they fill all available disk space on first boot. But you can create this file any time on any OPNsense installation.

Cheers
Maurice