Plesk is not accessible: Lock Manager error: 'No locks available'

Symptoms

• Plesk is installed in Virtual container.

• Plesk is not accessible with the following message in a browser:

  PLESK_INFO: Lock Manager error: 'No locks available'.
  Message Lock Manager error: 'No locks available'.
  File Hierarchical.php
  Line 126
  Type Plesk\Lock\Exception

• Virtual container limits shows the following:

  MYSQL_LIN: # grep -v " 0$" /proc/user_beancounters
  uid resource  held  maxheld  barrier limit failcnt
      numflock  1277  1280     1280    1680  4849192

Cause

Exceed numflock (number of locked files) in container.

Resolution

Increase virtual container limits.

1. For a Virtuozzo container, log in to Virtuozzo server using SSH.

2. Increase limits for numflock as in example below:

   # vzctl set <CT> --save --numflock 80000:90000