On Sun, 2012-09-09 at 10:21 +0100, Gordan Bobic wrote: <snip> > >> I never tried it, so I cannot comment either way. After the BTRFS devs > >> didn't manage to understand why CoW hard-links would be useful as a FS > >> feature (without vserver), and after some of the comments they made > >> regarding deduplication features and how (and whether) they plan to > >> implement it in BTRFS, I made a firm decision I'm not going to touch it > >> with a barge-pole. Ever. If these are the people designing and > >> developing the FS, I'm not prepared to entrust my data to it. Where my > >> requirements are feature-rich, I have switched to ZFS (ZFS-on-Linux > >> kernel driver, not the fuse implementation) and never looked back. I > >> still think it was the right decision. > > > > We've been using ZFS on OpenSolaris as I've heard the BSD implementation > > is poor and the FUSE implementation does not perform as well. I was not > > aware there was a ZFS-on-Linux kernel driver. I was under the > > assumption the licenses were incompatible and hence FUSE was the only > > Linux option. > > I haven't tried it, but from everything I've heard the BSD ZFS > implementation is _awesome_. It even has some features that the > OpenSolaris implementation lacks (e.g. TRIM/discard). FUSE > implementation is handy as a fallback option if you have a problem (make > sure you create a pool with version that can be accessed by all the > implementations you might want to try it on). > > As for licencng - yes, the ZFS licence means it cannot be shipped with > the mainline kernel, but there's nothing at all stopping it from being > shipped as an external module. > > And BSD people have a much more healthily pragmatic view of licencing > nit-picking in this sense, as is evident from the fact that they've had > ZFS support in their kernel for years. > > > Is this real ZFS on Linux? > > Yes. (As opposed to what? Fake ZFS on Linux?) As opposed to running it as a FUSE file system. > > > Does it compare in features and performance to OpenSolaris? > > Yes. > > > If so, I think it would be even better than OpenSolaris > > as it appears the network stack latency is lower in Linux than > > OpenSolaris from what we've seen. Thanks - John > > ZFS doesn't go anywhere near the network stack so I don't know what > exactly the connection here might be. Network latency for IOPS in a SAN. For small block sizes, I would think latency would be even more of an issue than bandwidth when talking to a ZFS based SAN. Then again, I suppose command tag queuing would coalesce those so latency would not be as critical. > > Gordan