SFTP mirroring can complicate home server backups
After an N100 mini PC failed, the Proxmox setup is being rebuilt and the backup tool is changing from Duplicati to Zerobyte. Zerobyte uses restic, and its and mirror option make the setup feel simpler. Zerobyte is running inside an LXC on Proxmox.
The storage targets include a local UNAS Pro, a local Synology 223 used for family photos and videos, and a remote Synology 213 connected through Tailscale. The UNAS Pro and Synology devices are attached as NFS shares for volumes. The UNAS Pro is mounted locally, while both Synology are mounted through SFTP.
A backup from the UNAS Pro to the local Synology 223, with a mirror to the remote Synology 213, fails because both destinations use SFTP backends with different , and Zerobyte suggests making a separate backup scheduler for the desired destination. Using the same SSH key does not fix the error. A working is to attach the local Synology 223 as a bind mount, which then allows the preferred local backup plus remote mirror setup.
Key points
- Zerobyte is being used as the backup tool inside an LXC on Proxmox.
- The setup includes one local UNAS Pro, one local Synology 223, and one remote Synology 213 over Tailscale.
- The mirror attempt fails when both backup destinations are SFTP with different .
- Changing SSH keys does not solve the reported error.
- Mounting the local Synology as a bind mount works as a .