unable to activate (SMB) storage for automatic lxc snapshot backup

RobinBonk

New Member
May 2, 2025
4
0
1
Hello everybody,
I ran into an issue where my lxc backups are not made reliably. Every so often I get an error that my backups were not succesfull since the storage location failed to activate:
Code:
00:00:14
got timeout
INFO: notified via target `mail-to-root`
TASK ERROR: could not activate storage 'barracuda': unable to activate storage 'barracuda' - directory '/mnt/pve/barracuda' does not exist or is unreachable

I have the current configuration:
- RPI3 with an external sata HDD connected over usb that hosts a SMB share called "barracuda".
- Home assistant on different RPI that also uses this smb-share for its (much smaller) backups. (daily at 00:00)
- Mini pc running proxmox with an lxc for my main stuff. I have added the smb-share into the storage locations on proxmox. I can inspect it and it is mounted correctly after restarting. It takes some time (like 7 seconds) before the actual content shows, since the disks have to spin up first.

I use rsync to sync my immich upload folder to the smb-share daily at also at 00:00.
I have also set up a daily backup tasks for my lxc in snapshot mode that uses smb-share also at 00:00.

The rsync and home assistant backups have never failed before. Just the automatic lxc backup fails. When I check in the mornings and notice the error, I perform a manual backup with the same settings as the automatic one and it does work.

I have set up my home assistant backup to start at 23:59 the disk is already spinning before proxmox tries to backup, but that also did not fix it.

I don't know what could be causing this.
 
Welcome!
1) Please post the definition of this storage.
2) The full command of the backup job.
3) Is the share actually mounted?
4) What is in /mnt/pve/barracuda ?
 
1) Please post the definition of this storage.
Bash:
cifs: barracuda
        path /mnt/pve/barracuda
        server 192.168.2.197
        share barracuda
        content backup
        prune-backups keep-all=1
        subdir /backups/docker ubuntu
        username robin
2) The full command of the backup job.
Code:
vzdump: backup-8baf63ca-6b2e
        comment automatic backup job at monday to friday at 0%3A00
        schedule mon..fri 00:00
        compress zstd
        enabled 1
        fleecing 0
        mode snapshot
        node pve
        notes-template {{guestname}}
        notification-mode notification-system
        prune-backups keep-last=3
        repeat-missed 0
        storage barracuda
        vmid 100
3) Is the share actually mounted?
Yes. I can acces the share in the proxmox GUI and see its content. It does take a few seconds for it to spin up though.
4) What is in /mnt/pve/barracuda ?
Proxmox sees these two folders on the smb-share barracuda:
/mnt/pve/barracuda/
dump <- for the lxc backups
immich <- for rsync task of immich upload folder


When manually creating a backup with "Backup now" using the same configuration it does work. Even when I explicitly wait for the disk to fully spin down to see if that has any effect on the outcome.
 
Thanks. Maybe the log of the backup job (without secrets, if any) in the SPOILER tags will give some trace...
 
Code:
cifs: barracuda
        path /mnt/pve/barracuda
...
        subdir /backups/docker ubuntu

I wonder if this /backups/docker ubuntu shouldn't be escaped somehow? I mean the space inside. Maybe /backups/docker\ ubuntu or in quotation marks "/backups/docker ubuntu" ? Just guessing...

Edit: there is no "password" line in the definition of the storage. Maybe you omitted this line entirely instead of obfuscating the password itself or isn't it there?...

You may also try to troubleshoot using some commands and tips from https://pve.proxmox.com/wiki/Storage:_CIFS and https://forum.proxmox.com/threads/how-to-add-smb-cifs-storage-to-proxmox-datacenter.109770/
 
Last edited:
I wonder if this /backups/docker ubuntu shouldn't be escaped somehow? I mean the space inside. Maybe /backups/docker\ ubuntu or in quotation marks "/backups/docker ubuntu" ? Just guessing...
When creating the folder I also looked into it. It apparently does work, but just for best practices I renamed it to /backups/docker_ubuntu now and re-added it.
Edit: there is no "password" line in the definition of the storage. Maybe you omitted this line entirely instead of obfuscating the password itself or isn't it there?...
By design, the passwords are stored elsewhere. For me it is located in: /etc/pve/priv/storage/barracuda.pw

Thank you for helping. I think that I correctly set up the smb-share due to it working when doing the manual "Backup now". Maybe there is some option to change the timeout check in proxmox and extend it.
 
By design, the passwords are stored elsewhere. For me it is located in: /etc/pve/priv/storage/barracuda.pw
You're right. Being in hurry, I misread the docs.

Maybe there is some option to change the timeout check in proxmox and extend it.

I've got a thought to setup at 23:59 some simple cron job like ls /mnt/pve/barracuda to wake up your disk, but as you've written that you already have other job at 23:59 so the disk is already spinning at 00:00, I'm out of ideas :confused:.
 
You're right. Being in hurry, I misread the docs.



I've got a thought to setup at 23:59 some simple cron job like ls /mnt/pve/barracuda to wake up your disk, but as you've written that you already have other job at 23:59 so the disk is already spinning at 00:00, I'm out of ideas :confused:.
Yeah, I am also a bit clueless as to why. For now I have moved my lxc backup job to 0:30 since no other jobs should be running at that time and I'll see if that has anything to do with it.