turning off <varname>fsync</varname>.

</para>

<para>

For reliable recovery when changing a cluster from

<varname>fsync</varname> off to on, it is necessary to force all

modified buffers in the kernel to durable storage. This can be

done while the cluster is shutdown or while fsync is on by running

<command>initdb --sync-only</command>, running <command>sync</>,

unmounting the file system, or rebooting the server.

</para>

<para>

In many situations, turning off <xref linkend="guc-synchronous-commit">

for noncritical transactions can provide much of the potential