Can you share your SSD products and ceph.conf?
In a test 3node cluster, 2ssds each intel s3500 i see very disappointing numbers. I maintain a 6 node cluster mixed ssd and sata pools. IOPS are not enough for a kvm hosting company unless you have really low values at disk io throttling. A big cluster is needed full of ssds for kvm selling that will make the price per vm unreachable for clients. For small offices it seems to me a good choice and the maintenance is really easy adding-removing osd, updating, rebooting nodes. > Date: Mon, 31 Aug 2015 08:06:37 +0200 > From: aderumier@xxxxxxxxx > To: lindsay.mathieson@xxxxxxxxx > CC: ceph-users@xxxxxxxxxxxxxx > Subject: Re: Is Ceph appropriate for small installations? > > >>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). > > > > ----- 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. > > > > > -- > Lindsay > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com |
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