[HowTo]: Mount Additional Storage in OMV LXC on Proxmox

[MickLesk]

Mounting Additional Storage in OMV LXC on Proxmox

This guide explains how to mount additional storage in an OpenMediaVault (OMV) container running on Proxmox Virtual Environment (PVE).

Prerequisites

• Proxmox Virtual Environment (PVE) host
• Existing OMV LXC container

Steps

1. Create OMV LXC Container

Create an OMV LXC container on your Proxmox host using the corresponding script. Ensure the container is set to "Privileged" during creation.

2. Add Storage Mount Point

1. Stop the OMV container.
2. In the Proxmox shell, add a mount point for additional storage:

   pct set <CT_ID> -mp0 local-lvm:10,mp=/data
   

   This will create a 10GB storage mount point at /data.

3. Find Block Device IDs

1. Run lvdisplay in the Proxmox shell.
2. Look for the Logical Volume like /dev/pve/vm-<CT_ID>-disk-X.
3. Note the "Block device" numbers, e.g., 253 9.

4. Create Mount Hook Script

1. Create the mount hook script file:

   echo '#!/bin/sh' > /var/lib/lxc/<CT_ID>/mount-hook.sh
   echo 'mknod -m 777 ${LXC_ROOTFS_MOUNT}/dev/sda1 b 253 9' >> /var/lib/lxc/<CT_ID>/mount-hook.sh
   

   Replace 253 9 with the block device numbers you found in the previous step.
2. Make the script executable:

   chmod a+x /var/lib/lxc/<CT_ID>/mount-hook.sh
   

5. Add Hook to LXC Config

Edit the LXC config file:

echo 'lxc.hook.autodev: /var/lib/lxc/<CT_ID>/mount-hook.sh' >> /etc/pve/lxc/<CT_ID>.conf

6. Start the OMV Container

Start the OMV container.

7. Mount the Storage

1. In the OMV web interface, go to "Storage" -> "File Systems".
2. Click "Mount existing file system" and add /dev/sda1.

At this point, the additional storage should be available in the OMV interface. You can then create shares, set permissions, and use the storage as needed.

Please note that some users reported issues with this method, particularly around the block device numbers changing after a reboot. In such cases, you may need to modify the mount hook script to use the LVM volume UUID instead of the block device numbers.

Original-Thread: tteck/Proxmox#1075

[Koliera]

Question - would this work with the scenario of just adding an existing hdd to an LXC? Such as adding an existing HDD to a jellyfin server LXC?
For VMs I usually just use the following - https://i12bretro.github.io/tutorials/0653.html
But unsure how to do the same to a LXC.

[NAM1025]

This does actually seem to work.

I found my block device info via lsblk for a drive that I was using in OMV in a VM (via disk passthrough) and just plugged it in... It recognized the drive in its entirety on OMV in the new LXC I setup.

Edit:
Found a script in the old thread linked in the OP.

I modified it to work with lsblk so that you could use the UUID to find the correct drive if you wanted to set it up this way.

#!/bin/sh
#MAJ_MIN=`lsblk -yn -o MAJ_MIN --filter "UUID == 'b581977e-ea73-48b9-a894-a8697d8c6d15'" | sed "s/:/ /g"`  # Needs a newer version of lsblk
MAJ_MIN=`lsblk -n -o "MAJ:MIN,UUID" | grep "b581977e-ea73-48b9-a894-a8697d8c6d15" -m 1 | sed "s/\([0-9]\+\)\:\([0-9]\+\).*/\\1 \\2/g"`

mknod -m 777 ${LXC_ROOTFS_MOUNT}/dev/sda1 b $MAJ_MIN

[ChrizZz90]

do I understand this correctly, that with using existing hdds I can skip points 1-3, starting directly with the 4th step and using this update with the UUID?

//edit: Yes, just starting with step 4 and use NAM1025 adjusted script with your own hdd UUID

[adriaanos]

Can confirm that the above by ChrizZz90 works.

My only problem now is once I create the share and want to write to any files that have already been created I get a permissions error. I have everything chown by 1005 so wondering how I do the same for lets say a random "samba" user here?

[Koliera]

I do wonder if the above might be created as a script similar to the tailscale one - as in you run the script, select lxc, select the hdd option you want to use from a generated list, and then done. Is that an option?

[n8ur]

I'm a little confused by a couple of things in the original post:

1. The prereq includes an existing OMV LXC container, but the first step is to create an OMV LXC. Do I make a second one, or is the prerequisite wrong?
2. On my system, doing lvdisplay in the proxmox shell shows three volumes: root, swap, and data. There's nothing with a name referencing a VM or a container. Where does that "vm-103-disk-1" reference come from, and what do I do in my situation?
3. I have a separate ZFS RAIDZ2 pool created which is where I'd like to put my OMV storage. How would I access that?

Thanks!

[blablazzz]

Could we have script for OpenMediaVault in VM?

[Koliera]

I'd say it should go beyond the OMV VM, because many different scripts would benefit from linking into the hdd.