Tuning Linux for Postgresql - Database failed to start

[Albin Ary <albinary10@xxxxxxxxx>]

Hello, 

I have a Postgresql Database cluster. 

Version: 14.2

OS: Oracle Linux 8

I tried to follow the link to optimize the server.

https://www.enterprisedb.com/blog/tuning-red-hat-enterprise-linux-family-postgresql 

Unfortunately, after rebooting the database is not starting anymore. I know the HINT is straightforward but I am not able to see what the reason could be. 

Any advice would be appreciated.

-- Unit postgresql-14.service has begun starting up.
May 10 22:10:40 postgersdb.localdomain postmaster[1612]: 2022-05-10 22:10:40.047 CEST [1612] FATAL:  could not map anonymous shared memory: Cannot allocate memory
May 10 22:10:40 postgersdb.localdomain postmaster[1612]: 2022-05-10 22:10:40.047 CEST [1612] HINT:  This error usually means that PostgreSQL's request for a shared memory segment exceeded available memory,>
May 10 22:10:40 postgersdb.localdomain postmaster[1612]: 2022-05-10 22:10:40.048 CEST [1612] LOG:  database system is shut down
May 10 22:10:40 postgersdb.localdomain systemd[1]: postgresql-14.service: Main process exited, code=exited, status=1/FAILURE
May 10 22:10:40 postgersdb.localdomain systemd[1]: postgresql-14.service: Failed with result 'exit-code'.
-- Subject: Unit failed
-- Defined-By: systemd
-- Support: https://support.oracle.com