Can't for the life of me get SSH-access from my Raspberry Pi

Hi all,

I'm using my OMV server as an offsite backup of the most important shares on my unRAID server using rsync. I've purchased a Raspberry Pi Zero that will be on the same network as my offsite OMV server, which runs Tailscale, so that way I'm able to send etherwake commands. This all works great! But I was looking into creating some bash scripts that allow for two different boot sequences. Namely one that enables autoshutdown after booting using crontab for scheduled backups, and the other that disables it after booting so I don't have to worry it shuts down when I'm just working on that server. In order to do that, I need to be able to SSH into the OMV server from the Raspberry Pi from the bash script. However, I can't for the life of me get it to work. The weird thing is that I've been able to setup ssh-keys for all my other computers to SSH into the OMV server. Except for the Raspberry Pi I keep getting the following:

username@raspberrypi:~ $ ssh root@192.168.1.145

root@192.168.1.145: Permission denied (publickey).

When checking the authorized_keys file on the OMV server I can clearly see the public key from the Raspberrry Pi. If I remember correctly I've put it there manually, as I've also tried copying the keys through the ssh-copy-id function, but then I'll receive the same error message as above ultimately.

Thanks for reading this, and I hope someone is able to shed some light on this.

PS: root access is enabled

Hi crashtest, thanks for your response and for approving the thread! It however is the other way around. I want the R-Pi to be able to SSH into the OMV server (not even necessarily root-level). 192.168.1.145 is the OMV server. With other devices I am able to SSH into the OMV server.