==== Required information ====
- iRedMail version (check /etc/iredmail-release): 0.9.8
- Linux/BSD distribution name and version:  CentOS 7
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): PGSQL
- Web server (Apache or Nginx): Nginx
- Manage mail accounts with iRedAdmin-Pro? yes pro 2.9.0
- [IMPORTANT] Related original log or error message is required if you're experiencing an issue.
====

May 07 13:20:23 mailserver.medhaj.com pg_ctl[15219]: FATAL:  could not create semaphores: No space left on device
May 07 13:20:23 mailserver.medhaj.com pg_ctl[15219]: DETAIL:  Failed system call was semget(5432129, 17, 03600).
May 07 13:20:23 mailserver.medhaj.com pg_ctl[15219]: HINT:  This error does *not* mean that you have run out of disk space.  It occurs when either the system limit for the maximum number of semaphore sets (SEMMNI), or the system wide maximum number of semaphores (SEMMNS), would be exceeded.  You need to raise the respective kernel parameter.  Alternatively, reduce PostgreSQL's consumption of semaphores by reducing its max_connections parameter.
May 07 13:20:23 mailserver.medhaj.com pg_ctl[15219]: The PostgreSQL documentation contains more information about configuring your system for PostgreSQL.

How can I raise limit for postgresql max connections as I have already raised it to 999.
But now it is showing me to change kernel parameter...
What to do ?