More mature than on Linux even, as far as I know. If I had to choose an OS to use ZFS with, I'd go with either FreeBSD or Solaris. That said, I am biased to FreeBSD anyway; the only Linux installation that I own is the one in my Android phone, while I own several FreeBSD systems.
> On Thu, Jan 16, 2014 at 4:22 AM, Sébastien Lorion <sl@thestrangefactory.com> > wrote: >> >> Hello, >> >> Since ZFS on Linux (http://zfsonlinux.org/) has been declared production >> ready last March (v0.6.1), I am curious if anyone is using it with >> PostgreSQL on production servers (either main or backup) and if so, what is >> their experience so far ? >> >> Thank you, >> >> Sébastien
I do not consider ZFS an ideal file-system for databases. I'm not an expert on ZFS, but there are two features in ZFS that I think particularly make it less suitable for database use.
One reason is that ZFS, as I understand it, is a log-structured file-system. That means that changes to files always go to the end of the file-system. If that file is a large frequently updated database table, records are going to be far apart and in fairly random order. That could seriously hurt performance.
Secondly, with ZFS you need to reserve a significant amount of memory for the ZIL. That is memory that is not available to your database.
Don't take my word for it, but I think the above points are worth investigating as is finding some file-system bench- marks where ZFS gets compared to, for example, UFS2 (FreeBSD), Ext4fs (Linux). Of course, the other side of the coin is ZFS's excellent flexibility.
Cheers,
Alban Hertroys -- If you can't see the forest for the trees, Cut the trees and you'll see there is no forest.
Those are very good points, but from my own tests and recent TPC benchmarks I saw on the net (sorry, don't have the links anymore), using SSD makes them not/less an issue. As you say, ZFS flexibility and ease of maintenance trumps many cards. Also, something worth pointing out and which may be counter-intuitive is that using ZFS compression can actually speed things up: http://citusdata.com/blog/64-zfs-compression