[nowwhat]

OU exactement t'as trouvé ce fichier ?
Le chemin exact ?

edit : sorry wrong language mode.
Where did you found this file 'dmsg' ?
The exact path ?

[paranormalium]

Ok, found dmesg, here's what it says:
pastebin.com/HhdpG18W

[paranormalium]

Ok, found dmesg, here's what it says:

http://pastebin.com/HhdpG18W

[paranormalium]

My OS is 'Linux Plesk 12.5 (CentOS 7) (64bits)'.

[nowwhat]

.....
EDIT: Again, 'server does not ping after reboot'

Your server won't reply to ping when for example, it doesn't boot (well).
The admin - this is you - should mount the partitions - to access YOUR data - and inspect the logs used when booting.
You mount your partitions in /mnt/, so you log files might be here /mnt/var/log/.... (might, because you didn't say what OS you use - "'Plesk" is just a program that only works if your server works - Plesk goes away with the slightest problem ...)
Look for the file called 'dmesg' - ans see what happened.
Other logs might exists. Check out ALL recent logs (the ones that were used / created when it was boot time)..

[paranormalium]

In the KS Manager you instructed that KS should check you server (with a regular ping)

Honestly, I don't even know how to do this. I only remember setting up mod_security in Plesk, but in the Manager I haven't changed anything. I can't even see the option to enable regular pinging.

As I said, test on my_server_ip:81 has been completed, it found no errors, now I'm trying to reboot my server from my hard disk.

EDIT: Again, 'server does not ping after reboot'

[paranormalium]

Test on my_server_ip:81 completed, no errors found

[paranormalium]

In the KS Manager you instructed that KS should check you server (with a regular ping)

I don't even know how to do that... and I don't see such option in the Manager

Right now I'm doing tests on my_server_ip:81.

Before, I have tried mounting all partitions, and only Linux system partition has been mounted properly, and the partition containing contents of my website says the following:

root@rescue:~# mount /dev/sda3 /mnt/
mount: /dev/sda3 is write-protected, mounting read-only
NTFS signature is missing.
Failed to mount '/dev/sda3': Invalid argument
The device '/dev/sda3' doesn't seem to have a valid NTFS.
Maybe the wrong device is used? Or the whole disk instead of a
partition (e.g. /dev/sda, not /dev/sda1)? Or the other way around?

[nowwhat]

I've tried to reboot my server from HDD, however, in 'Tasks' section I see error message with the following comment: 'Server does not ping after reboot'.

This is probably why the server was been put into rescue mode.
It could be a simple issue like : In the KS Manager you instructed that KS should check you server (with a regular ping) and you blocked this ping (firewall) on your server. KS 'thinks' you server is down, and reboots it into rescue mode.
Or, worse, your drive died, so the OS died, so the server did't reply anymore, so it was put in rescue mode.

Right now, you can't do this : https://forum.kimsufi.com/showthread...To-Rescue-Mode
You should read this FIRST (you are gona need it) : https://forum.kimsufi.com/showthread...ans-le-manager (I didn't find a English version, but I guess it exists).
The basics :
Generate a public and private key.
The private key should be on your PC (MAC, whatever).
The public key goes to he Manager (see the tutorail where to put it).
Reboot your server (into rescue mode) again from the Manager.
Use your SSH client (Putty on a PC, or the native SSH client on a MAC), and instruct it to uses your private key : you can login into your server without entering a (root) password !!!!

Only after that you'll be ready for the real question : finding out why your server was been put into rescue mode.
Do a hardware check.
SAVE your data.

When all is done, and your server is up again, booted from YOUR hard disk, change the setup your SSH service so it uses the public key. You will never ever need the root password again - you might as well forget it. USE your private key to login. You be save, for ever. You don't need to receive the mail any more.
This is how modern OS's are accessed today ..... "password auth" usage has been ditched a long time ago.
KS, when delivering your server, send you a mail. The (root) password in this mail should be used only ones ....

[paranormalium]

I've tried to reboot my server from HDD, however, in 'Tasks' section I see error message with the following comment: 'Server does not ping after reboot'.

[paranormalium]

RBX1 - Rack: 17F07
Server ID: 119036

Some two hours ago there occured some failure which resulted in my server being unavailable. Now the servers seems working, however, it has been put in 'rescue mode' and I cannot log in to Plesk and FTP, nor I can visit any of my websites.

From what I've read, a notification email should have been sent with temporary login data, however, due to problems with my email server I'm unable to check my mailbox right now. I've already checked my additional email and I haven't found any messages from Kimsufi there.

I would be very grateful if you could help me. I just need my server to be put back in normal functionality.