On 10/10/2018 21:50, Bruce Momjian wrote: >> I see. Peter is proposing to have a fourth mode, essentially >> --transfer-mode=clone-or-copy. > > Uh, if you use --link, and the two data directories are on different > file systems, it fails. No one has ever asked for link-or-copy, so why > are we considering clone-or-copy? Are we going to need > link-or-clone-or-copy too? I do realize that clone and copy have > non-destructive behavior on the old cluster once started, so it does > make some sense to merge them, unlike link.
I'm OK to get rid of the clone-or-copy mode. I can see the confusion. The original reason for this behavior was that the Linux implementation used copy_file_range(), which does clone-or-copy without any way to control it. But the latest patch doesn't use that anymore, so we don't really need it, if it's controversial. -- Peter Eisentraut http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
