The system detected an installer lock file: (/root/installer.lock) Make certain that an installer is not already running.

Uncompressing Cpanel & WHM Installer…..
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Installer Version v00055 r36da1e5a15fba715f3b72c219b5a1b7191e3d57e

Beginning main installation.
The system detected an installer lock file: (/root/installer.lock)
Make certain that an installer is not already running.

You can remove this file and re-run the cPanel installation process after you are certain that another installation is not already in progress.

root 9576 0.0 0.0 2980 1048 pts/1 S+ 21:38 0:00 sh -c ps auxwww |grep 9494
root 9578 0.0 0.0 2276 548 pts/1 S+ 21:38 0:00 grep 9494
[root@server home]#

How to Fix the above error ?

I saw the above error while trying to install cPanel control panel on my CentOS server. Error shows that there might an installer already running on your server. Type the command “ps auxwf” to check whether any cPanel installation is going on. “ps auxwf” command will list all process running on your linux server. You can remove the lock file /root/installer.lock and re-run the cPanel installation process after you are certain that another installation is not already in progress. You can remove the installer lock file using the below command

Command : rm -f /root/installer.lock
 

 
After removing the lock file you can start cPanel installation and you wont see the same error. Run the below command to restart cPanel installation.

Command : cd /home && curl -o latest -L https://securedownloads.cpanel.net/latest && sh latest
 

 
cPanel installation will take 20-50 minutes, depending on your server hardware.