On Thu, Jun 25, 2020 at 5:23 PM Paul Förster <paul.foerster@xxxxxxxxx> wrote:
Hi Ken,
> On 25. Jun, 2020, at 17:15, Wolff, Ken L <ken.l.wolff@xxxxxxxx> wrote:
> There's actually a lot of good stuff in that document about Postgres in general. I'd be curious to hear what everyone thinks, though, and specifically about what NetApp recommends in Section 3.3 about putting data and WAL on separate volumes, which I believe contradicts what's been discussed in this email thread.
yes, I've read the part about different volumes and I must say, I don't agree because I think it violates atomicity.
I believe NetApp does atomic snapshots across multiple volumes, if you have them in the same consistency group. (If you don't then you're definitely in for a world of pain if you ever have to restore)
Snapshotting multiple volumes in a consistency group will set up a write fence across them, then snapshot, and AIUI guarantees correct write ordering.
