On Friday 05 November 2010 22:53:37 Greg Smith wrote:
> > If open_dsync is so bad for performance on Linux, maybe it's bad
> > everywhere? Should we be rethinking the default preference order?
> >
> >
>
> And I've seen the expected sync write performance gain over fdatasync on
> a system with a battery-backed cache running VxFS on Linux, because
> working open_[d]sync means O_DIRECT writes bypassing the OS cache, and
> therefore reducing cache pollution from WAL writes.
Which looks like a setup where you definitely need to know what you do. I.e.
don't need support from wal_sync_method by default being open_fdatasync...
Andres