Does proxmox-backup-client make a snapshot first or just copy the files?

[Rxunique]

Not sure if this is a noob question, I don't have a deep understanding FS snapshots.

All my docker containers are running with bind mounts on ubuntu VM on PVE nodes with ZFS, and been learning about backup. I've read that its best to stop docker database containers before making backup to ensure consistency, but FS level snapshot (ZFS) doesn't have this worry.

So I thought of 2 approach using

proxmox-backup-client backup disk1.pxar:/mnt/disk1

1. Install proxmox-backup-client to VM and call it on VM level.
2. Create zfspool/dataset_vm1 on PVE node, mount it in VM with NFS, and call proxmox-backup-client on PVE node

I'm not sure if either level actually using ZFS snapshot? Or just copy the files? Or if there's some method to test?

Preferably I'd want the docker bind mount to stay in VM rather than NFS mounts, that makes VM migration and replication and HA much simpler to deal with

It is also possible just create 2nd VM disk to be backed up with PBS while excluding the OS disk, but I don't think PBS allow viewing or exporting single file if done this way

 

[Chris]

Not sure if this is a noob question, I don't have a deep understanding FS snapshots.

All my docker containers are running with bind mounts on ubuntu VM on PVE nodes with ZFS, and been learning about backup. I've read that its best to stop docker database containers before making backup to ensure consistency, but FS level snapshot (ZFS) doesn't have this worry.

So I thought of 2 approach using

proxmox-backup-client backup disk1.pxar:/mnt/disk1

1. Install proxmox-backup-client to VM and call it on VM level.
2. Create zfspool/dataset_vm1 on PVE node, mount it in VM with NFS, and call proxmox-backup-client on PVE node

I'm not sure if either level actually using ZFS snapshot? Or just copy the files? Or if there's some method to test?

Preferably I'd want the docker bind mount to stay in VM rather than NFS mounts, that makes VM migration and replication and HA much simpler to deal with

It is also possible just create 2nd VM disk to be backed up with PBS while excluding the OS disk, but I don't think PBS allow viewing or exporting single file if done this way

Hi, no if you use the proxmox-backup-client, than there is no snapshotting using the underlying filesystem (this is handled by the vzdump logic if you use PVE backup jobs with snapshot mode).

None of your two presented options do perform a snapshot, the latter will also suffer from performance issue because of the additional network layer. May I ask what your motivation is to perform the backup on the VMs filesystem level and not directly using the provided backup functionality of Proxmox VE for this?

It is also possible just create 2nd VM disk to be backed up with PBS while excluding the OS disk, but I don't think PBS allow viewing or exporting single file if done this way

Note that single file restore is possible also for VM disks, provided the restore VM is able to mount the filesystem, which is mostly possible.

 

[Rxunique]

Thanks for your reply.

My goal is figuring out a solid backup for docker bind mounts across various VM. And ideally be able to access the file just as if in a file browser

A lot of docker stack will have mysql or postgres or mariadb container which is the tricky part. Hence i was thinking snapshot.

I know of scripting to shut down container to do proper backup, but hoping not to do that.

Also the possibility of scripting db to dump/export while running, but stopping container would be much streamlined then this approach.