Cannot access Cpanel nor SSH after upgrade/reboot

[pmoby]

Hello,

I ordered a brand new VPS from our hosting provider (OVH). About 10 hosted sites were copied from an older version of Cpanel and obsolete Centos OS. I also applied the advised SSH port change from OVH and could then perfectly connect in SSH to say the 63000 port, plus the Fail2ban module, only set to monitor SSH, and with our IPs whitelisted. I could actually use the new VPS until I had to reboot it: updates were advised, so I did them.
After upgrading to Cpanel V100 as suggested in the GUI, the server stopped replying. Reboot never completed ? No Cpanel nor SSH connection could be regained, server lost.

I ordered a new empty VPS and installed one test hosting account, then applied only security updates thinking maybe the cpanel V100 version caused issues.
The "Graceful server reboot" started with "A reboot is now in progress", last thing I ever saw. Once again lost access to Cpanel port 2087, and SSH access times out too. That was tested from several machines and providers / IPs of course, tested with and without SSL /httpS.
I know the VPS OS still works because the single user hosting I created still replies and can be connected to (on port 2083 not 2087), and we receive cronjobs reports.
At 04:45 am, we received

"[vps-xxxxxxx.vps.ovh.net] cPanel & WHM update failure in upcp script
Maintenance ended; however, it did not exit cleanly (256). The following events were logged: “scripts/rpmup”. Review the update logs to determine why the update failed.
[2022-01-19 03:44:23 +0000] E [/usr/local/cpanel/scripts/rpmup] The “/usr/local/cpanel/scripts/rpmup” command (process 16600) reported error number 1 when it ended."

What goes wrong ?
I could not submit a ticket because Cpanel support requires a "Support Access ID" which can only be found in the server by Web access or SSH, doh.

Thanks.

 

[cPanelAnthony]

Hello! Would you be able to perform some network testing steps? If the SSH port and 2087 are unresponsive, it sound like a potential firewall or networking issue. You can use tools like "telnet" or "nmap" to test connectivity from your local machine to these ports.

https://support.cpanel.net/hc/en-us/articles/360036533474-How-to-troubleshoot-network-issues

 

[quietFinn]

Have you tried to connect using KVM?
You find it in Your VPS -> Name ... KVM

 

[pmoby]

Thanks for the replies. Being blocked from my own SSH I have of course a very limited set of options, and the KVM option is pending verification.
As far as tools from another VPS are concerned, I could gather the following:

[email protected]:~#


telnet: Unable to connect to remote host: Network is unreachable

Nmap scan report for vpsname.ovh.net 
PORT   STATE  SERVICE VERSION
22/tcp closed ssh
Too many fingerprints match this host to give specific OS details
Network Distance: 12 hops

[email protected]:~# nmap r -p 65100
Starting Nmap 7.80 ( https://nmap.org ) at 2022-01-20 08:32 UTC
Host is up (0.00078s latency).

PORT      STATE    SERVICE
65100/tcp filtered unknown

Nmap done: 1 IP address (1 host up) scanned in 0.18 seconds

Thanks.

 

[pmoby]

After the graceful reboot from Cpanel that lead to that downtime, the reboot through KVM was also tried to no avail.

 

[cPanelAnthony]

Hello! Seeing the "closed" status in nmap for port 22 indicates that SSH runs on a different port, which is what we already know and expect. When you ran it on port 65100, it gave a "filtered" status which indicates the firewall is blocking the incoming connections. If 65100 is the SSH port, I can definitely say there is some type of firewall problem; at least between the device you ran the nmap test on and your server.