Resolved Migration connection issue

[ashley]

Server operating system version

Almalinux 10 target. Centos 7 source

Plesk version and microupdate number

18.0.74 Target 18.0.57 source

I am trying to start a migration but it fails at connection. Obsidian to Obsidian migration.

Error message is "Failed to check SSH connection to the source server 'source' (IP ADDR):"

SSH keys generated on target and pub key copied to source authorized_keys file.

I can ssh from target to source fine. So firewall fine. I can also use the SSH terminal within plesk and that connects fine.

When i use migration tool i receive the error message.

On source i see the following error in /var/log/secure

sshd[7316]: dispatch_protocol_error: type 90 seq 3 [preauth]

I just migrated an identical (probably!) server to the problem one without issue.

Web trawling isn't helping figure this out. Maybe someone has an idea!?

 

[Sebahat.hadzhi]

Hello, @ashley . Is root login permitted on the servers? Please try executing the following command on the source and destination servers:

grep -i permitrootlogin /etc/ssh/sshd_config

 

[ashley]

Yes, as mentioned i can run ssh at command prompt and in Plesk SSH terminal using just

#ssh [IP ADDR}

 

[Maarten]

Can you check the info.log and debug.log for errors in /usr/local/psa/var/modules/panel-migrator/sessions/<date>/*

 

[ashley]

info.log is claiming no connection
[ERROR] Unable to connect to 'IP ADDR' by SSH: not a valid OPENSSH private key file. Retrying in 10 seconds

debug.log saying the same
core.utils.ssh_utils|||Unable to connect to 'IP ADDR' by SSH: not a valid OPENSSH private key file. Will exclude old keys hashing algorithms and try again.
core.utils.ssh_utils|||Exception:

So migrator doesnt like the private key file whereas standard connection works?

 

[Maarten]

Could be different things.
- How did you create the ssh-key? With the same type as the other servers?
- Did you check the file- and directory permissions of the .ssh directory and the files inside .ssh/*? Those are very strict.

 

[ashley]

Thanks for your help. I clearly did something wrong and because ssh worked at command line i got blind to the basics, Started at the beginning again and now working.

 

[Maarten]

No problem, I'm glad it works now!