[SOLVED] VM and CT have simply vanished

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nick90

New Member
Apr 28, 2025
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Hi There,

I've got a Dell Optiplex 7080 with Proxmox 8.3.5 installed. There is a external 14TB hard drive attached to it which store all of my VM. Unfortunately the power got cut out this afternoon & this shutoff the system. When I got online I noticed my OMV Nas wasn't up & running. I've looked into the VM & noticed that none of my VM are running. When I attempt to run the VM it state that the volume doesn't exist.

Upon some research I discovered that the uuid has changed for my external hard drive & I was able to remount it. However, upon looking in the new mount of the drive. I've noticed that the drive doesn't contains any of my VM anymore. I haven't even delete it & they're gone.

Here is a screenshot of the directory for the file

1745830654195.png

I understand that sometime the disk can unmount itself but this shouldn't cause the vm & containers to go pff & disapear, just like a magic trick. This drive is also shared with my OMV which those files are retained but not the VM & Containers for Proxmox.

Everytime I attempt to start one of my VM, I simply cannot get it started here is the file config of one of the VM. Any assistance will be greatly appriciate it

1745830787901.png
 
Hey,

is it actually mounted correctly? What is the output of mount, and lsblk? How do you mount it? /etc/fstab?
 
Hannes Laimer said:
Hey,

is it actually mounted correctly? What is the output of mount, and lsblk? How do you mount it? /etc/fstab?
Click to expand...
Mount provide me the following
1745832487730.pnglsblk show me the drive mounted under sdb
1745832548719.png

I mount it using the following command
mount /dev/disk/by-uuid/2f152f8f-87bb-4e1b-987c-a4a444913335 /mnt/pve/DIR01
I've attached my fstab config for your reference as well
1745832772010.png
 
Are you sure 2f152f8f-87bb-4e1b-987c-a4a444913335 is correct?
Code: 
ls -lah /dev/disk/by-uuid/2f152f8f-87bb-4e1b-987c-a4a444913335
should be a link to /dev/sdb.

Currently the disk is not mounted, which explains /mnt/pve/DIR01 being empty.

Generally, if the disk is always connected, maybe consider mounting it using fstab, that way you wouldn't have to do it manually after every reboot.
 
Hannes Laimer said:
Are you sure 2f152f8f-87bb-4e1b-987c-a4a444913335 is correct?
Code: 
ls -lah /dev/disk/by-uuid/2f152f8f-87bb-4e1b-987c-a4a444913335
should be a link to /dev/sdb.

Currently the disk is not mounted, which explains /mnt/pve/DIR01 being empty.

Generally, if the disk is always connected, maybe consider mounting it using fstab, that way you wouldn't have to do it manually after every reboot.
Click to expand...
That is correct
1745834581877.png

When I create the fstab record for the drive, I'm not sure what the type that I should configure, dumps or pass. All I know it that setup as a directory. I'm looking to mount it without losing all of the contents.
1745834739205.png
 
It is not necessary to use fstab. Proxmox should create a systemd-file like /etc/systemd/system/mnt-pve-DIR01.mount, when you add the storage as directory.
Content is like
Code: 
[Install]
WantedBy=multi-user.target

[Mount]
Options=defaults
Type=vfat
What=/dev/disk/by-uuid/2f152f8f-87bb-4e1b-987c-a4a444913335
Where=/mnt/pve/DIR01

[Unit]
Description=Mount storage 'DIR01' under /mnt/pve

*filesystem type is just my guess from your fstab picture.
 
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If you created the fs through PVE then yes, what @fba said is correct. And updating the UUID in /etc/systemd/system/mnt-pve-DIR01.mount should be enough. After you updated the UUID you can run
Code: 
systemctl start mnt-pve-DIR01.mount
which should mount it. You can check if it is mounted with lsblk or mount.
 
How is it possible for a storage device to change its UUID without formatting or manual change it? UUIDs are used precisely to prevent the arbitrary renaming of sdaX to sdaY. I'm curious.
 
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TErxleben said:
How is it possible for a storage device to change its UUID without formatting or manual change it? UUIDs are used precisely to prevent the arbitrary renaming of sdaX to sdaY. I'm curious.
Click to expand...
Well I'm an complete idiot this case. I forgot that I have my images & lxc containers are stored on a 2TB nvme SSD, not on the external hard drive *faceplam*. The external Hard Drive is only used for my omv server.

It been a while that I played with my proxmox machine. Turned out that the 2TB nvme SSD wasn't being regonised by Proxmox & I needed to remove the drive from the slot for proxmox to detect it again. Once the nvme drive was detected, I was able to change the mount back by using the UUID of the nvme drive & everything is running back as normal. (Expect for my omv image, but that was my fault :))

tldr, Ensure all of your drives are detected properly & don't make major changes until you ensure your hardware is working correctly.
 
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