Server unreachable

The following article describes how diagnostic is done in order to check private or dedicated server breakdown.

Go to our works page first MAGIC or NUXIT which contains details of all technical interventions and incidents. If there is no failure, follow the steps on this support article.

Server down

Check the server ip

If one of the services, or your private server, seems to be malfunctioning, you should first check that it can be reached by the network:

Type the following command from a shell ( under windows → execute → cmd.exe):

ping

If the packets are not correctly transmitted then :

  • Check the Internet connection, by testing another server:
  ping google.com
  • Connect one last time to server by SSHand as a last resort, restart the server from the client area.

Check the DNS of the domain name

A website reachable on the Internet implies that the name → IP association is functional:

From the shell of your dedicated server, simply type the following command to verify that the recursion is working properly DNS :

dig +short  @

The last IP of the result returned must be the IP of your dedicated server. If this is not the case, please check the renewal status of your domain in the customer area.

Reachable server

Check disk quota

Disk space saturation can cause server problems, making services unavailable.

On a dedicated server

Run these commands online, from the CLI console:

  • Disk space:
df -h
  • Inodes:
df -i

On a private Plesk server

The Plesk manager offers the possibility to check the quota. Also, from the command line, you can run these commands online, from the CLI console:

  • Disk space:
df -h
  • Inodes:
df -i

On a private server without Plesk

Run these commands online, from the CLI console:

  • Disk space:
df -h
  • Inodes:
df -i

Check the largest directory 

To determine where the data occupying your disk space is located you can type the following command:

cd /
du -sh *

In case, for example, /var occupies too much disk space move to the directory and reiterate the command :

cd /var
du -sh *

And so on.

Do not delete just any data to free up disk space. Instead, ask your system administrator, our support, or even Google for advice.

Display of used resources

From the shell type the following command:

top

You will see a list of processes sorted by decreasing CPU usage, so the first process is the one that consumes the most CPU on your server. Usually the biggest consumer will be MySQL or Apache, but it can also be a process like a running backup or an action launched by Plesk on your system.

The left column gives you the process ID of the process in question, if you feel that this process is not vital and hinders the proper functioning of your system you can kill it directly from top, by typing the letter k followed by the ID.

You can also sort processes by decreasing RAM usage by typing the letter "M", so you can spot and kill a process that would monopolize all your physical memory.

To exit top simply type the letter "q".

Updated on 16 May 2022

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