On Wed, Apr 13, 2022 at 8:05 AM Thomas Munro <thomas.mu...@gmail.com> wrote: > On Wed, Apr 13, 2022 at 3:57 AM Dagfinn Ilmari Mannsåker > <ilm...@ilmari.org> wrote: > > Simon Riggs <simon.ri...@enterprisedb.com> writes: > > > This is a nice feature if it is safe to turn off full_page_writes.
> > > When is it safe to do that? On which platform? > > > > > > I am not aware of any released software that allows full_page_writes > > > to be safely disabled. Perhaps something has been released recently > > > that allows this? I think we have substantial documentation about > > > safety of other settings, so we should carefully document things here > > > also. > > > > Our WAL reliability docs claim that ZFS is safe against torn pages: > > > > https://www.postgresql.org/docs/current/wal-reliability.html: > > > > If you have file-system software that prevents partial page writes > > (e.g., ZFS), you can turn off this page imaging by turning off the > > full_page_writes parameter. > > Unfortunately, posix_fadvise(WILLNEED) doesn't do anything on ZFS > right now :-(. Update: OpenZFS now has this working in its master branch (Linux only for now), so fingers crossed for the next release.
