On Sat, 14 May 2016 09:46:23 -0700 Mike Jacobacci wrote:
Hello, > Hi Alex, > > Thank you for your response! Yes, this is for a production > environment... Do you think the risk of data loss due to the single node > be different than if it was an appliance or a Linux box with raid/zfs? > Depends. Ceph by default distributes 3 replicas amongst the storage nodes, giving you fault tolerances along the lines of RAID6. So (again by default), the smallest cluster you want to start with is 3 nodes. OF course you could modify the CRUSH rules to place 3 replicas based on OSDs, not nodes. However that only leaves you with 3 disks worth of capacity in your case and still the data movement Alex mentioned when adding more nodes AND modifying the CRUSH rules. Lastly I personally wouldn't deploy anything that's a SPoF in production. Christian > Cheers, > Mike > > > On May 13, 2016, at 7:38 PM, Alex Gorbachev <a...@iss-integration.com> > > wrote: > > > > > > > >> On Friday, May 13, 2016, Mike Jacobacci <mi...@flowjo.com> wrote: > >> Hello, > >> > >> I have a quick and probably dumb question… We would like to use Ceph > >> for our storage, I was thinking of a cluster with 3 Monitor and OSD > >> nodes. I was wondering if it was a bad idea to start a Ceph cluster > >> with just one OSD node (10 OSDs, 2 SSDs), then add more nodes as our > >> budget allows? We want to spread out the purchases of the OSD nodes > >> over a month or two but I would like to start moving data over ASAP. > > > > Hi Mike, > > > > Production or test? I would strongly recommend against one OSD node > > in production. Not only risk of hang and data loss due to e.g. > > Filesystem issue or kernel, but also as you add nodes the data > > movement will introduce a good deal of overhead. > > > > Regards, > > Alex > > > > > >> > >> Cheers, > >> Mike > >> > >> > >> _______________________________________________ > >> ceph-users mailing list > >> ceph-users@lists.ceph.com > >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > > > -- > > -- > > Alex Gorbachev > > Storcium > > -- Christian Balzer Network/Systems Engineer ch...@gol.com Global OnLine Japan/Rakuten Communications http://www.gol.com/ _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com