Mount existing backup drive on new PBS installation

[iacus]

Hi, I recently reinstalled Proxmox and PBS (same host). I have an existing external drive with backups for containers and VMs from my previous installation.

I see the drive is showing up in Proxmox, but I don't know how I can add it as a datastore. All the options seem to require a freshly wiped drive, which I want to hopefully avoid.

 

[cheiss]

Hi,

adding it back to PBS can be easily done manually, see e.g. https://forum.proxmox.com/threads/datastore-recovery.72835/#post-325491
Be sure to use an absolute path to the directory that contains the .chunks folder.

First you also need to mount the filesystem somewhere, but that depends on what filesystem you use exactly.

 

[iacus]

Thank you,

Manually you mean via editing the cfg files as opposed to thru GUI right?

When I do that, how can I get the storage to show up in PVE as well?

 

[cheiss]

Manually you mean via editing the cfg files as opposed to thru GUI right?

Yes, as lined out in the liked thread comment.

When I do that, how can I get the storage to show up in PVE as well?

After that, you should be able to normally add your PBS to your PVE cluster as usual.

 

[Chris]

Manually you mean via editing the cfg files as opposed to thru GUI right?

To add to @cheiss's answer: since PBS version 3.2.9 you can also do this in the GUI. Just go to Add Datastore > Advanced > Reuse existing datastore. Make sure the filesystem containing the datastore is mounted correctly first.

Edit: fixed version since when reusing datastores is available via GUI.

 

[Patrick B]

To add to @cheiss's answer: since PBS version 3.2.9 you can also do this in the GUI. Just go to Add Datastore > Advanced > Reuse existing datastore. Make sure the filesystem containing the datastore is mounted correctly first.

Edit: fixed version since when reusing datastores is available via GUI.

Hi Chris.

I have the same issue.
Our current PBS instance is unavailable. I created a new one and mounted the synology network share (cifs) to the PBS instance. However, when i try to add the datastore from the share, i get a permision error.
From what i've read, it seems the problem is that the share is mounted as root. Is that right ?
Could you please let me know what we need to do to attach the existing share to a new PBS instance ?

 

[Chris]

I created a new one and mounted the synology network share (cifs) to the PBS instance. However, when i try to add the datastore from the share, i get a permision error.

If possible use NFS instead of CIFS, while it is not recommended to use network attached storages for performance and fault tolerance reasons, NFS is known to perform better and more reliably with PBS than CIFS shares.

Also please share the exact error.

From what i've read, it seems the problem is that the share is mounted as root. Is that right ?
Could you please let me know what we need to do to attach the existing share to a new PBS instance ?

How did you mount the share? PBS requires the files and folder of a datastore to be owned by user and group backup

 

[Patrick B]

If possible use NFS instead of CIFS, while it is not recommended to use network attached storages for performance and fault tolerance reasons, NFS is known to perform better and more reliably with PBS than CIFS shares.

Also please share the exact error.


How did you mount the share? PBS requires the files and folder of a datastore to be owned by user and group backup

Hi Chris.
Thank you for the quick reply.

I have replaced the cifs connection with an nfs connection with the command:
mount -t nfs 100.xx.xxx.xxx:/volume1/vmbackups/backups /mnt/nas01
(ip hidden)

This is the directory listing for that mount:


I then try to add the datastore like this:


It returns this error:


Then, I found the bindfs utility which overrides the user and group on a share and used the command:
bindfs --force-user=34 --force-group=34 /mnt/nas-nfs /mnt/nas-bind

Now, the directory listing looks like this:


I try to add the datastore:


But I get the same error:


Now I am stuck as I don't know what else I need t modify.

Thank you for your help.

 

[Chris]

Then, I found the bindfs utility which overrides the user and group on a share and used the command:
bindfs --force-user=34 --force-group=34 /mnt/nas-nfs /mnt/nas-bind

This should not be needed and is actually counter-productive performance wise. Please do mount the NFS directly as you did previously. Did you try to set the ownership to user and group backup:backup which is user and group ID 34? Might be necessary to set permissions on the NFS server.

But I get the same error:

Permissions on the files and folders are still not correct. The datastore folder is expected to have 755, the chunk store folders including .chunks foldere and subfolders 750. Try adapting these with chmod accordingly.

 

[JanN]

My solution to set the correct permissions for the reuse of an existing datastore on a new PBS installation: https://forum.proxmox.com/threads/pbs-new-instance-add-existing-datastore-errors.165693/post-805759