HI Jan, On Tue, Aug 18, 2015 at 5:00 AM, Jan Schermer <j...@schermer.cz> wrote: > I already evaluated EnhanceIO in combination with CentOS 6 (and backported > 3.10 and 4.0 kernel-lt if I remember correctly). > It worked fine during benchmarks and stress tests, but once we run DB2 on it > it panicked within minutes and took all the data with it (almost literally - > files that werent touched, like OS binaries were b0rked and the filesystem > was unsalvageable).
Out of curiosity, were you using EnhanceIO in writeback mode? I assume so, as a read cache should not hurt anything. Thanks, Alex > If you disregard this warning - the performance gains weren't that great > either, at least in a VM. It had problems when flushing to disk after > reaching dirty watermark and the block size has some not-well-documented > implications (not sure now, but I think it only cached IO _larger_than the > block size, so if your database keeps incrementing an XX-byte counter it will > go straight to disk). > > Flashcache doesn't respect barriers (or does it now?) - if that's ok for you > than go for it, it should be stable and I used it in the past in production > without problems. > > bcache seemed to work fine, but I needed to > a) use it for root > b) disable and enable it on the fly (doh) > c) make it non-persisent (flush it) before reboot - not sure if that was > possible either. > d) all that in a customer's VM, and that customer didn't have a strong > technical background to be able to fiddle with it... > So I haven't tested it heavily. > > Bcache should be the obvious choice if you are in control of the environment. > At least you can cry on LKML's shoulder when you lose data :-) > > Jan > > >> On 18 Aug 2015, at 01:49, Alex Gorbachev <a...@iss-integration.com> wrote: >> >> What about https://github.com/Frontier314/EnhanceIO? Last commit 2 >> months ago, but no external contributors :( >> >> The nice thing about EnhanceIO is there is no need to change device >> name, unlike bcache, flashcache etc. >> >> Best regards, >> Alex >> >> On Thu, Jul 23, 2015 at 11:02 AM, Daniel Gryniewicz <d...@redhat.com> wrote: >>> I did some (non-ceph) work on these, and concluded that bcache was the best >>> supported, most stable, and fastest. This was ~1 year ago, to take it with >>> a grain of salt, but that's what I would recommend. >>> >>> Daniel >>> >>> >>> ________________________________ >>> From: "Dominik Zalewski" <dzalew...@optlink.net> >>> To: "German Anders" <gand...@despegar.com> >>> Cc: "ceph-users" <ceph-users@lists.ceph.com> >>> Sent: Wednesday, July 1, 2015 5:28:10 PM >>> Subject: Re: [ceph-users] any recommendation of using EnhanceIO? >>> >>> >>> Hi, >>> >>> I’ve asked same question last weeks or so (just search the mailing list >>> archives for EnhanceIO :) and got some interesting answers. >>> >>> Looks like the project is pretty much dead since it was bought out by HGST. >>> Even their website has some broken links in regards to EnhanceIO >>> >>> I’m keen to try flashcache or bcache (its been in the mainline kernel for >>> some time) >>> >>> Dominik >>> >>> On 1 Jul 2015, at 21:13, German Anders <gand...@despegar.com> wrote: >>> >>> Hi cephers, >>> >>> Is anyone out there that implement enhanceIO in a production environment? >>> any recommendation? any perf output to share with the diff between using it >>> and not? >>> >>> Thanks in advance, >>> >>> German >>> _______________________________________________ >>> ceph-users mailing list >>> ceph-users@lists.ceph.com >>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>> >>> >>> >>> _______________________________________________ >>> ceph-users mailing list >>> ceph-users@lists.ceph.com >>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>> >>> >>> _______________________________________________ >>> ceph-users mailing list >>> ceph-users@lists.ceph.com >>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>> >> _______________________________________________ >> ceph-users mailing list >> ceph-users@lists.ceph.com >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
