Hi Christian, Thank you, I know what I am asking isn't a good idea... I am just trying to avoid waiting for all three nodes before I began virtualizing our infrastructure. Again thanks for the responses! Cheers, Mike > On May 14, 2016, at 9:56 AM, Christian Balzer <chibi@xxxxxxx> wrote: > > 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 <ag@xxxxxxxxxxxxxxxxxxx> >>> wrote: >>> >>> >>> >>>> On Friday, May 13, 2016, Mike Jacobacci <mikej@xxxxxxxxxx> 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@xxxxxxxxxxxxxx >>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>> >>> >>> -- >>> -- >>> Alex Gorbachev >>> Storcium > > > -- > Christian Balzer Network/Systems Engineer > chibi@xxxxxxx Global OnLine Japan/Rakuten 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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