Impossible to rename a domain: Unable to rename home of sysuser

Symptoms

• The following error occurs when renaming a domain in Home > Domains > example.com > Hosting Settings:
  

  PLESK_ERROR: Error: Unable to rename home of sysuser with id=8: Unable to execute usermng: usermng[14704]: pam_unix(passwd:johndoe): password changed for johndoe usermod: user johndoe is currently used by process 21332

• PHP handler is set to PHP-FPM server by nginx in Home > Domains > example.com > PHP Settings.
• There are processes running under the user johndoe:
  

  # ps auxx | grep johndoe
  johndoe   21332  3.0  0.0 513636 16416 ?        S    01:22  0:00 php-fpm: pool example.com
  johndoe   21334  2.5  0.0 513504 15400 ?        S    01:22  0:00 php-fpm: pool example.com
  johndoe   21341  4.0  0.0 513504 15348 ?        S    01:22  0:00 php-fpm: pool example.com

Cause

The domain user johndoe is used by PHP-FPM processes

Resolution

Apply the following steps:

1. Connect to the server via SSH;
2. Change the PHP handler for the domain example.com in Home > Domains > example.com > PHP Settings to any non-FPM;

3. Check if there are processes running for user johndoe:  

   # ps auxx | grep johndoe
   johndoe   21332  3.0  0.0 513636 16416 ?        S    01:22  0:00 php-fpm: pool example.com
   johndoe   21334  2.5  0.0 513504 15400 ?        S    01:22  0:00 php-fpm: pool example.com
   johndoe   21341  4.0  0.0 513504 15348 ?        S    01:22  0:00 php-fpm: pool example.com
   root     21347  0.0  0.0 112660  972 pts/0    S+  01:22  0:00 grep --color=auto club

4. Kill such processes:

   # kill -9 21332 21334 21341

5. Rename the domain in question.

6. Set PHP handler for the domain example.com to PHP-FPM server by nginx in Home > Domains > example.com > PHP Settings.