/etc/rc.d/rc.sysinit: fork: Cannot Allocate Memory error after reboot Oracle linux

One of our customer need to decreased server RAM from 128Gb to 32 Gb.

After closing database, We rebooted server. While server trying to open it gave below error message:

Here is the solution for this error:

1. Check below files for hugepages config

cat /etc/sysctl.conf |grep -i huge
vm.nr_hugepages = 38903

cat /etc/sysctl.d/99-initial-sysctl.conf |grep -i huge vm.nr_hugepages = 5000

cat /etc/sysctl.d/99-oracle-rdbms-server-12cR1-preinstall-sysctl.conf |grep -i huge vm.nr_hugepages = 5000

Found these miss-configuration from the data collected

2. Update/Edit files and set the kernel parameter value “same” everywhere.
3. Reboot server

References:
HugePages Not Getting Allocated Correctly After Server Reboot (Doc ID 2610185.1)
Server Hung During Boot With Error ‘/etc/initd/functions: fork: Cannot allocate memory’ (Doc ID 2276510.1)
How to Collect sosreport under Rescue Mode (Doc ID 1928852.1)