Dtyjlui

I upgraded my remote hosted server from 16.04 to 18.04. The first steps seemed to go fine without any errors or warnings. Until the reboot step.

I confirmed the reboot step. After this the ssh connection got closed of course. I waited for at least 4 hours (I don't know exactly how long, but minimum 4 hours), but I still couldn't got any ssh and sftp connections.

I can

• successfully ping the server


• make hard reboots via the web UI from my hoster



• I know for a fact that cronjobs are still running




• I get every few minutes emails with errors from the cronjobs (Boinc got uninstalled in the upgrade process so it obviously can't be started; and the Nextcloud cronjob fails since Postgres doesn't seem to be running)



• since it is a remote server and I don't have any access I can't run any commands or read/write any files

I'm normally using a connection manager, but in the hope to get some more information than "connection refused" I also tried directly to execute it in the console, result:

[croydon ~]$ ssh -vvv <sever-ip>

OpenSSH_7.9p1, OpenSSL 1.1.1 FIPS  11 Sep 2018

debug1: Reading configuration data /etc/ssh/ssh_config

debug3: /etc/ssh/ssh_config line 52: Including file /etc/ssh/ssh_config.d/05-redhat.conf depth 0

debug1: Reading configuration data /etc/ssh/ssh_config.d/05-redhat.conf

debug3: /etc/ssh/ssh_config.d/05-redhat.conf line 2: Including file /etc/crypto-policies/back-ends/openssh.config depth 1

debug1: Reading configuration data /etc/crypto-policies/back-ends/openssh.config

debug3: gss kex names ok: [gss-gex-sha1-,gss-group14-sha1-,gss-group1-sha1-]

debug3: kex names ok: [curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,diffie-hellman-group1-sha1]

debug1: /etc/ssh/ssh_config.d/05-redhat.conf line 8: Applying options for *

debug2: resolve_canonicalize: hostname <sever-ip> is address

debug2: ssh_connect_direct

debug1: Connecting to <sever-ip> [<sever-ip>] port 22.

debug1: connect to address <sever-ip> port 22: Connection refused

ssh: connect to host <sever-ip> port 22: Connection refused

I read that Ubuntu 18.04 doesn't accept some older ciphers, but I guess this log rules this potential issue out.

Is there any hope for recovery, if so what can I do?

Actually, turned out my provider has a rescue mode in which I could figure out the problem and fix it.

The OpenSSH version got update to a newer one. My OpenSSH configuration was invalid with the current version. I needed to remove hmac-ripemd160 from the MAC list and that was all (at least for this problem).

OpenSSH should really working on better error messages and/or upgrade processes. Getting locked out is not that much fun.