the kernel setting <varname>vm.nr_hugepages</varname>. To estimate the

number of huge pages needed, start <productname>PostgreSQL</productname>

without huge pages enabled and check the

postmaster's<varname>VmPeak</varname> value, as well as the system's

postmaster'sanonymous shared memory segment size, as well as the system's

huge page size, using the <filename>/proc</filename> file system. This might

look like:

<programlisting>

$ <userinput>head -1 $PGDATA/postmaster.pid</userinput>

4170

$ <userinput>grep ^VmPeak /proc/4170/status</userinput>

$ <userinput>pmap 4170 | awk '/rw-s/ &amp;&amp; /zero/ {print $2}'</userinput>

$ <userinput>grep ^Hugepagesize /proc/meminfo</userinput>

Hugepagesize: 2048 kB

</programlisting>