How to find the number of huge pages to set on a PostgreSQL server

Thanks to Ibrar Ahmed for posting the article "Tune Linux Kernel Parameters For PostgreSQL Optimization"

Log on to the server as the os user that owns the PostgreSQL server. On my server, this user is called "postgres":

su - postgres

Create a file called find_hp.sh. Insert the following:

#!/bin/bash
pid=`head -1 $PGDATA/postmaster.pid`
echo "Pid:            $pid"
peak=`grep ^VmPeak /proc/$pid/status | awk '{ print $2 }'`
echo "VmPeak:            $peak kB"
hps=`grep ^Hugepagesize /proc/meminfo | awk '{ print $2 }'`
echo "Hugepagesize:   $hps kB"
hp=$((peak/hps))
echo Set Huge Pages:     $hp

Make sure the environment variable $PGDATA is set. Give the script execution rights:

chmod 755 find_hp.sh

Execute it, and it will tell you how many huge pages you need:

 ./find_hp.sh
Pid:             128678
VmPeak:          68986484 kB
Hugepagesize:    2048 kB
Set Huge Pages:  33684

I can now proceed to allow for 33684 huge pages on my system with

sysctl -w vm.nr_hugepages=33684