Mounting NFS share to Proxmox Backup Server LXC

[Depechie]

Does anyone have a working setup, where you pass a NFS share to the Proxmox Backup Server so you can use that as datastore?
No matter what I try to create the datastore, I always get EPERM: Operation not permitted.

I pass the NFS path in the /etc/fstab of the Proxmox PVE host and then pass that path as a mount in the LXC config file.
So in the terminal of Proxmox Backup Server, I'm able to see the mounted path and even use it. In other words create dirs and files. But that terminal runs underneath the root user of Proxmox Backup Server and the backup process and datastore is done underneath user backup with UID 34.
So I guess that is somehow the problem, but it is a guess and I'm not sure.

Or what do other users do with the Proxmox Backup Server LXC?

[knario]

Hi, I have a pbs on a lxc with a ssd run through nfs and it works fine.
I used to have pbs on a vm, as I don't have another server to be able to mount it apart.
This way I am solving the lack of another server until I can buy it.
The way I did it is:

• First: I installed nfs on the same proxmox host:

  • apt update
  • apt install nfs-kernel-server

• Second: I created the necessary folders and permissions. Example:

  • mkdir -p /mnt/backup
  • chown nobody:nogroup /mnt/data
  • chmod 755 /mnt/data

• Third: I edited the export file to be able to export the folder to my network.

  • nano /etc/exports
    The contents of the exports file.
    /mnt/data 192.168.88.0/24(rw,sync,no_subtree_check)

Change the network to the one in your case and apply the changes. ;-)

 - exportfs -arv

• Start and enable the nfs service:
  • systemctl start nfs-kernel-server
  • systemctl enable nfs-kernel-server

---

• Now in the pbs lxc install nfs:
  - apt update
  - apt install nfs-common

• Now create the mount point and mount the share in the fstab file.

  • mkdir -p /mnt/nfs

• nano /etc/fstab
  192.168.88.1:/mnt/data /mnt/nfs nfs defaults 0 0

In my case, it gave me an error when mounting it in the pbs, so I had to chmod -R 755 from proxmox to the nfs folder /mnt/backups.
Now it works fine, the backups are done well and it takes up little memory.
One consideration, you must have the disk you are going to use for the pbs empty, otherwise you will get an error.
I don't know if it has anything to do with it, but in proxmox I have everything set up by lvm.

I hope I helped you. If you have more doubts tell me here :-)

[Depechie]

Woow @knario thx for the details...
My setup is slightly different, so I guess that could cause some problems? Let me explain maybe we can identify it...

In my case the starting point is different. The location that I want to use is a NFS share on my NAS and to get that into Proxmox PVE I do the following.
In the Proxmox PVE shell

mkdir /mnt/backups

nano /etc/fstab
192.168.1.20:/mnt/backups /mnt/backups nfs defaults 0 0

nano /etc/pve/lxc/101.conf
mp0: /mnt/backups,mp=/mnt/backups

With that the NFS path is mounted onto the Proxmox PVE and passed as a mount point to the PBS LXC.
I did not do any chowns... but I map all users to root on the NFS share in Synology.
So in both the PVE shell and the PBS shell I can create dirs and files manually in the /mnt/backups but PBS keeps saying permission error.

Do you think I first need to chown the backups folder in PVE before I edit the fstab?
Afterwards it keeps saying I'm not allowed...

[knario]

Hello! I think the problem comes more from the nfs export file. I'll tell you how I have it, change the ip for your range.

cat /etc/exports
/mnt/backups2 192.168.88.0/24(rw,sync,no_subtree_check,no_root_squash)
/mnt/backups3 192.168.88.0/24(rw,sync,no_subtree_check,no_root_squash)

---

The hdd's for the pbs are mounted as normal ext4.
this is part of the /etc/fstab file of proxmox

#Backups SSD Samsumg Gb
UUID=“xxxxxxxxxxxxxxxxx” /mnt/backups ext4 nofail,auto,rw 0 0
#/mnt/backups2 (Toshiba 250Gb SSD)
UUID=“xxxxxxxxxxxxxxxxxxxxyxyxyxyxyxyxyxyyx” /mnt/backups2 ext4 nofail,auto,rw 0 0 0

I did not configure the pbs datastore.cfg file because at the beginning it gave me an error, I preferred to add the datastore directly.

---

see also if this command works for you, looking at the pbs terminal history I used it.
chown -R root:root /mnt/backups2

chmod -R 700 /mnt/backups2
chown -R root:root /mnt/backups2

change the path to yours

Let's see if we have any luck

[Depechie]

Well... on Synology defining NFS is done in the UI and not directly in the /etc/exports
But I can show you the actual settings

/volume1/Storage    192.168.1.40(rw,async,no_wdelay,crossmnt,insecure,all_squash,insecure_locks,sec=sys,anonuid=1024,anongid=100)  
192.168.1.156(rw,async,no_wdelay,crossmnt,insecure,all_squash,insecure_locks,sec=sys,anonuid=1024,anongid=100)  
192.168.1.41(rw,async,no_wdelay,crossmnt,insecure,all_squash,insecure_locks,sec=sys,anonuid=1024,anongid=100)  
192.168.1.159(rw,async,no_wdelay,crossmnt,insecure,all_squash,insecure_locks,sec=sys,anonuid=1024,anongid=100)

For the other part, any chmod or chown on PVE or PBS results in permission denied. ( when the mounts are set ).

[knario]

Then it may be that the problem comes from the synology, that does not export the empty hdd from synology by nfs.
You can do something, if you have another old hdd, mount it in proxmox, export that folder by nfs and try to create the datastore in pbs.
Just to rule out where the problem comes from.