On 08/31/2015 08:06 AM, Alexandre DERUMIER wrote: >>> True, true. But I personally think that Ceph doesn't perform well on >>> small <10 node clusters. > > Hi, I can reach 600000 iops 4k read with 3 nodes (6ssd each). > True, but your performance is greatly impacted during recovery. So a three node cluster might work well when the skies are clear and the sun is shining, but it has a hard time dealing with a complete node failure. > > > ----- Mail original ----- > De: "Lindsay Mathieson" <lindsay.mathieson@xxxxxxxxx> > À: "Tony Nelson" <tnelson@xxxxxxxxxxxxx> > Cc: "ceph-users" <ceph-users@xxxxxxxxxxxxxx> > Envoyé: Lundi 31 Août 2015 03:10:14 > Objet: Re: Is Ceph appropriate for small installations? > > > On 29 August 2015 at 00:53, Tony Nelson < tnelson@xxxxxxxxxxxxx > wrote: > > > > > I recently built a 3 node Proxmox cluster for my office. I’d like to get HA setup, and the Proxmox book recommends Ceph. I’ve been reading the documentation and watching videos, and I think I have a grasp on the basics, but I don’t need anywhere near a petabyte of storage. > > > > I’m considering servers w/ 12 drive bays, 2 SDD mirrored for the OS, 2 SDDs for journals and the other 8 for OSDs. I was going to purchase 3 identical servers, and use my 3 Proxmox servers as the monitors, with of course GB networking in between. Obviously this is very vague, but I’m just getting started on the research. > > > > > > I run a small 3 node Proxmox cluster for our office as well with Ceph, but I'd now recommend against using Ceph for small setups like ours. > > - Maintenance headache. Ceph requires a lot of tweaking to get started and a lot of ongoing monitoring, plus a fair bit of skill. If you're running the show yourself (as typical in small businesses) its quite stressful. Who's going to fix the ceph cluster when a osd goes down when you're on holiday? > > - Performance. Its terrible on small clusters. I've setup a iSCSI over ZFS for a server and its orders of magnitude better at I/O. And I haven't even configured multipath yet. > > - Flexibility. Much much easier to expand or replace disks on my ZFS server. > > The redundancy is good, I can reboot a ceph node for maintenance and it recovers very quickly (much quicker than glusterfs), but cluster performance suffers badly when a node is down so in practice its of limited utility. > > I'm coming to the realisation that for us performance and ease of administration is more valuable than 100% uptime. Worst case (Storage server dies) we could rebuild from backups in a day. Essentials could be restored in a hour. I could experiment with ongoing ZFS replications to a backup server that makes that even quicker. > > Thats for use - your requirements may be different. And of course once you get into truly large deployments, ceph comes into its own. > > > > -- Wido den Hollander 42on B.V. Ceph trainer and consultant Phone: +31 (0)20 700 9902 Skype: contact42on _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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