Server down after restart

[Deker]

Hello,

Today I found that my root password is changed (may be hacked) and I counldn't access to SSH and WHM.
So I used remote console to reset the root password and then rebooted the server.
But after rebooting, the server does not start anymore! no ping, no ssh and completely down.
I asked the DC for a manually hardware restart but they told me "We restarted the server, however it was not possible to start the installed system." !
Any idea that what's wrong with my server? It seems a software issue because the server was working fine before I reboot it.

 

[JaredR.]

It is impossible to tell what is wrong without access to the server. Since it is offline, you will need to work with your data center on this. They can put a console (display and keyboard) on the server, which will let them run commands and view the output, and possibly restore SSH access.

Unfortunately, there is really no way to give any useful advice with such limited information. There could be any number of things wrong, and only your data center has the access needed to do any real troubleshooting.

 

[Deker]

The service is self-managed so they dont help their customers in such situations
Can an incomplete kernel update cause this issue? If yes is there anything I can do to downgrade the kernel to previous version?
I used yum

 

[JaredR.]

There are a number of things that can cause a problem like this, and it is just not possible to guess without access.

A problem with the kernel can cause the server not to boot. Usually, if a new kernel is installed, the old one is not removed; the new one just takes its place in the boot order. Your data center, using the console, can pick an older kernel to boot from the grub menu that is displayed during the boot process. If that causes the server to boot, you can then edit your grub.conf file to use the kernel that does boot in the future.

Please understand that this is really not cPanel related, and this is not the best forum to discuss it, since it concerns the operating system at a very low level before cPanel even enters the scene. Whatever you do is going to require access, and that means your data center is going to need to help you, since as you stated, the server is not online.

 

[Deker]

I understand and sorry for posting in wrong forum
however I asked the dc but they rejected me
Is it possible to downgrade the kernel via KVM?

 

[benz1ne]

Deker, How did you reset via remote console? My server company is the same, they set up Remote Access (LARA) and I want to reset my WHM Password... any help would be appreciated.

 

[JaredR.]

The root password for the WHM is the server's root password; root is literally the same user for both the shell and the WHM, so there is no separate "WHM password". You can reset the root password using the passwd command from the shell while logged in as root.

 

[Deker]

Deker, How did you reset via remote console? My server company is the same, they set up Remote Access (LARA) and I want to reset my WHM Password... any help would be appreciated.

You need to use rescue mode to change root password. check the link bellow:
Hetzner Rescue-System/en