On 2015-03-22 12:54:37 -0700, Josh Berkus wrote: > On 03/22/2015 06:45 AM, Andres Freund wrote: > > FWIW, I think that's a myth. One I heard various versions of by now. As > > long as the OSs page size (4kb nearly everywhere) is different from > > postgres' (8kb) you can have torn pages. Even if individual filesystem > > page writes are atomic. > > ZFS's block size is larger than Linux's memory page size. That is, ZFS > on Linux uses a 8kB to 128kB block size depending on which blocks you're > looking at and how you have it configured. Does that make a difference > at all, given that Linux's memory page size is still 4kB?
No, it does not make a differencen. The page cache is still 4kb. > FYI, the BTRFS folks are also claiming to be torn-page-proof, so it > would be really nice to settle this. Not sure how to force the issue > through testing though. I don't think this applies here. Greetings, Andres Freund -- Andres Freund http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (email@example.com) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers