I have set up an Rsync job to backup my Nextcloud data folder (NC on a Raspberry Pi, Raspbian Stretch, on my local network) to my OMV server (Debian Stretch, OMV 4.1.19). So far I did the following:
As the Nextcloud data folder is owned by www-data, I created a user "NCrsync" on the Pi and added it to the www-data group
In the OMV GUI, I created a new SSH key and tried to copy the public key to the Pi which failed as the GUI can't handle the "Trust this RSA key" prompt. So I created the file /home/NCrsync/.ssh/authorized_keys on the Pi, copied the public key from the OMV GUI and pasted it into this file
Set up an Rsync job in the OMV gui with the following settings:
Type: Remote
Mode: Pull
Source server: NCrsync@<pi-ip>:/media/hdd1/data
Destination folder: shared folder on my OMV server
Authentication: Public key
SSH port: 22
SSH certificate: nc-rsync
However, if I start the Rsync job, it fails:
Please wait, syncing <NCrsync@<pi-ip>:/media/hdd1/data> to <path-on-server> ...
Host key verification failed.
rsync: connection unexpectedly closed (0 bytes received so far) [Receiver]
rsync error: unexplained error (code 255) at io.c(235) [Receiver=3.1.2]
The synchronisation has completed successfully.
Done ...
What could be the reason for this to fail?
Thank you very much in advance!