rdiff-backup error: Host key verification failed

Question

What is this error? This rdiff-backup command is run in a shell script. How to resolve this issue?

 ssh -l root 161.3.46.12 rdiff-backup [email protected]::/root/files/1/ /root/cloodon_sync spawn ssh -l root 161.3.46.12 rdiff-backup [email protected]::/root/files/1/ /root/cloodon_sync [email protected]'s password: Host key verification failed. Fatal Error: Truncated header string (problem probably originated remotely) Couldn't start up the remote connection by executing ssh -C [email protected] rdiff-backup --server Remember that, under the default settings, rdiff-backup must be installed in the PATH on the remote system. See the man page for more information on this. This message may also be displayed if the remote version of rdiff-backup is quite different from the local version (1.0.5). 

Answer 1

It looks like your connection is failing because the ssh host key of your target host has changed:

Host key verification failed. 

Because of this error your ssh connection is failing. You need to either update the cached host key on your local system, or figure out why the host key on the remote system has changed. You can update your local key like this:

# ssh-keygen -R 161.3.46.12 # ssh [email protected] 

This should prompt you to accept the new host key.

Do note that host key verification is a fatal error for a reason; it can mean that your remote server has been compromised. More often it means that someone has re-installed a system without preserving the host key.

Answer 2

Did you read the error message?

rdiff-backup must be installed in the PATH on the remote system. See the man page for more information on this. This message may also be displayed if the remote version of rdiff-backup is quite different from the local version (1.0.5).

In other words, check that

• you have rdiff-backup installed on the remote server,
• the versions of rdiff-backup on the local and remote sites are not too different, and
• rdiff-backup is on the PATH of the user running it on the remote side (in your case, on the root user's PATH).