Different operations on Plesk for Linux server fail: /usr/sbin/usermod execution failed: usermod: user is currently used by process

Symptoms

• On a Plesk for Linux server, different operations like:

  • renaming the subscription's system user in Domains > example.com > Hosting & DNS > Hosting;
  • modifying settings of an additional FTP user in Domains > example.com > FTP;
  • renaming a domain;
  • restoring a Plesk backup;
  • deleting a web user;

  fail with the error like below which can be also found in the log file /var/log/plesk/panel.log and/or in the "Network" tab of the browser's DevTools:

  external server error

  ---

  SysUser::update() failed: Unable to execute usermng: usermng: /usr/sbin/usermod execution failed: usermod: user johndoe is currently used by process 4758 usermng: Unable to modify user: johndoe

  ---

  Unable to execute usermng: usermng: /usr/sbin/userdel execution failed: userdel: user johndoe is currently used by process 4382 usermng: Unable to delete user: johndoe

  ---

  usermod: user johndoe is currently used by process 2367804
  usermng: Unable to modify user: johndoe

• The PHP handler FPM application is set as a PHP handler in the menu Domains > example.com > PHP.

Cause

Resolution

Workaround

Until the bug is fixed, use the workaround:

1. Log in to Plesk.

2. Perform one of the following actions in each domain of the affected subscription:

   • Change the PHP handler to FastCGI application: go to Domains > example.com > PHP and in the option run PHP as, change the handler from FPM application to FastCGI application, and click OK or Apply at the bottom of the page.

     

   • Disable PHP: go to Domains > example.com > PHP, disable the option PHP support, and click OK or Apply at the bottom of the page.

3. Suspend the affected subscription.

4. Connect to the server using SSH.

5. If Cgroups Manager is installed and enabled, disable it:

   # plesk sbin resctrl --disable

6. Execute the following command, replacing $username with the name of the subscription's system user:

   # killall -TERM -u $username; sleep 1; killall -KILL -u $username

   Note: to find the subscripton's system user name, check the field Username under System user's credentials in the menu Domains > example.com > Hosting & DNS > Hosting.

7. In the Plesk interface, perform the operation that was failing.

8. Revert changes made in steps 2, 3, and 5.

   Note: for reverting step 5, execute the command plesk sbin resctrl --enable.