On Mon, 27 Oct 2014 15:13:30 +0100 Sebastien Han wrote: > They were some investigations as well around F2FS > (https://www.kernel.org/doc/Documentation/filesystems/f2fs.txt), the > last time I tried to install an OSD dir under f2fs it failed. I tried to > run the OSD on f2fs however ceph-osd mkfs got stuck on a xattr test: > > fremovexattr(10, "user.test@5848273") = 0 > > Maybe someone from the core dev has an update on this? > That looks interesting, but wouldn't Ceph also need to be told that this can be used journal-less like BTRFS? Along those lines, I would love to hear the current status of ZFS with Ceph. From where I'm standing BTRFS just isn't getting there, while ZFS would give us checksummed storage, the possibility to forgo journals and also compression. The last bit being of interest to me, as I'm trying to position Ceph against SolidFire here. Christian > > On 24 Oct 2014, at 07:58, Christian Balzer <chibi@xxxxxxx> wrote: > > > > > > Hello, > > > > as others have reported in the past and now having tested things here > > myself, there really is no point in having journals for SSD backed > > OSDs on other SSDs. > > > > It is a zero sum game, because: > > a) using that journal SSD as another OSD with integrated journal will > > yield the same overall result performance wise, if all SSDs are the > > same. And In addition its capacity will be made available for actual > > storage. b) if the journal SSD is faster than the OSD SSDs it tends to > > be priced accordingly. For example the DC P3700 400GB is about twice > > as fast (write) and expensive as the DC S3700 400GB. > > > > Things _may_ be different if one doesn't look at bandwidth but IOPS > > (though certainly not in the near future in regard to Ceph actually > > getting SSDs busy), but even there the difference is negligible when > > for example comparing the Intel S and P models in write performance. > > Reads are another thing, but nobody cares about those in journals. ^o^ > > > > Obvious things that come to mind in this context would be the ability > > to disable journals (difficult, I know, not touching BTRFS, thank you) > > and probably K/V store in the future. > > > > Regards, > > > > Christian > > -- > > Christian Balzer Network/Systems Engineer > > chibi@xxxxxxx Global OnLine Japan/Fusion Communications > > http://www.gol.com/ > > _______________________________________________ > > ceph-users mailing list > > ceph-users@xxxxxxxxxxxxxx > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > Cheers. > –––– > Sébastien Han > Cloud Architect > > "Always give 100%. Unless you're giving blood." > > Phone: +33 (0)1 49 70 99 72 > Mail: sebastien.han@xxxxxxxxxxxx > Address : 11 bis, rue Roquépine - 75008 Paris > Web : www.enovance.com - Twitter : @enovance > > -- Christian Balzer Network/Systems Engineer chibi@xxxxxxx Global OnLine Japan/Fusion Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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