Re: Two patches to speed up pg_rewind.

On Wed, Jun 02, 2021 at 05:02:10PM +0900, Michael Paquier wrote:

> On Wed, Jun 02, 2021 at 06:20:30PM +1200, Thomas Munro wrote:

> > The main thing I noticed was that Linux < 5.3 can fail with EXDEV if

> > you cross a filesystem boundary, is that something we need to worry

> > about there?

>

> Hmm.  Good point.  That may justify having a switch to control that.

Paul, the patch set still needs some work, so I am switching it as

waiting on author.  I am pretty sure that we had better have a

fallback implementation of copy_file_range() in src/port/, and that we

are going to need an extra switch in pg_rewind to allow users to

bypass copy_file_range()/EXDEV if they do a local rewind operation

across different FSes with a kernel < 5.3.

--

Michael