sshfs backup duplicates network traffic?

[djxx]

I am configuring my backup to use sshfs and noticed this while it was running:

Copying /mnt/cloudronbackup/snapshot/mail.tar.gz to /mnt/cloudronbackup/2025-07-27-215345-102/mail_v8.3.2.tar.gz

On the remote server I can see the snapshot and timestamped directory (e.g. 2025-07-27-215345-102) while the backup is running.

Based on the network traffic, it seems that while it is moving each file from snapshot to the timestamped directory, it is literally using copy, which means the file has to make another round trip. If I'm not mistaken, this means the network usage for this backup will be 3x the size of the file.

It seems like this is happening:

1. Cloudron makes an archive
2. Cloudron sends this file to the snapshot folder
3. Cloudron receives the file back again (part of copy)
4. Cloudron sends the file again to the timestamped folder (part of copy)

Wouldn't it be much more efficient (and faster) to issue a mv command to move the file rather than have a round trip?

Also, it seems like another side effect is the snapshot folder keeps the files there until the next run - requiring 2x the space for the backup.

[james]

Hello @djxx
With this commit https://git.cloudron.io/platform/box/-/commit/d122ece8e9afb9d6209057fe35e2056c11e90061

Attempt server side copy on sshfs via ssh exec

Was introduced and after that enhanced with:
https://git.cloudron.io/platform/box/-/commit/44678cf5f128d8d43e02076b40a1a32bd29c29a1

sshfs: if remote copy fails, fallback to sshfs based copy

So, sshfs tries to issue a remote copy command but falls back to sshfs based copy if it fails for some reason.

What is your provider for sshfs? Most people here use Hetzner Storage Boxes.

[girish]

@djxx We already fixed this in the latest release where we try to do a server side copy . Initially we thought sshfs was smart enough to do this by itself (being FUSE) but apparently not.

[djxx]

@james said in sshfs backup duplicates network traffic?:

So, sshfs tries to issue a remote copy command but falls back to sshfs based copy if it fails for some reason.

What is your provider for sshfs? Most people here use Hetzner Storage Boxes.

I'm my own provider I'm just using a standard SSH install on proxmox, and the files are stored on a ZFS cluster. I don't know of anything that would stop the copy command from working; what can I do to check / troubleshoot this?