401 authentication failure when adding node to cluster


New Member
May 19, 2023

I would appreciate your assistance with an issue I'm facing while trying to add a new node to my current 5-node cluster. Everything went smoothly for the previous nodes, but now I've encountered the following error using both the GUI and CLI:

root@proxmox-d02:~# pvecm add
Please enter superuser (root) password for '': ********************
Establishing API connection with host ''
The authenticity of host '' can't be established.
X509 SHA256 key fingerprint is C9:84:FC:A3:59:53:97:F7:7A:75:EF:83:00:A7:DE:84:92:A2:08:62:04:24:D3:D4:B2:6B:3B:6C:0E:11:CC:6B.
Are you sure you want to continue connecting (yes/no)? yes
401 authentication failure

I can confirm that the password is correct, and I've double-checked it. I also checked the know_hosts files like /etc/pve/priv/know_hosts.

However, I'm unable to locate the specific log file that contains more detailed information about this authentication failure.

Any guidance or assistance in resolving this issue would be greatly appreciated. Thank you in advance for your help.

Last edited:
Hello, did you check the known_hosts file on all the nodes, what about `~/.ssh/known_hosts`?

Is it possible that you already had a node with the same host name but different ssh key? e.g. if you reinstalled the OS on that node.


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