To start safely you need a replication factor of 3 and at least 4 nodes (think size+1) to allow for smooth maintenance on your nodes.
On Fri, Jul 1, 2016 at 2:31 PM, Ashley Merrick <[email protected]> wrote: > Hello, > > Okie makes perfect sense. > > So if run CEPH with a replication of 3, is it still required to run an odd > number of OSD Nodes. > > Or could I run 4 OSD Nodes to start with, with a replication of 3, with > each replication on a separate server. > > ,Ashley Merrick > > -----Original Message----- > From: ceph-users [mailto:[email protected]] On Behalf Of > Tomasz Kuzemko > Sent: 01 July 2016 13:28 > To: [email protected] > Subject: Re: [ceph-users] CEPH Replication > > Still in case of object corruption you will not be able to determine which > copy is valid. Ceph does not provide data integrity with filestore (it's > planned for bluestore). > > On 01.07.2016 14:20, David wrote: > > It will work but be aware 2x replication is not a good idea if your > > data is important. The exception would be if the OSD's are DC class > > SSD's that you monitor closely. > > > > On Fri, Jul 1, 2016 at 1:09 PM, Ashley Merrick <[email protected] > > <mailto:[email protected]>> wrote: > > > > Hello, > > > > Perfect, I want to keep on separate node's, so wanted to make sure > > the expected behaviour was that it would do that. > > > > And no issues with running an odd number of nodes for a replication > > of 2? I know you have quorum, just wanted to make sure would not > > effect when running an even replication. > > > > Will be adding nodes in future as require, but will always keep an > > uneven number. > > > > ,Ashley > > > > -----Original Message----- > > From: ceph-users [mailto:[email protected] > > <mailto:[email protected]>] On Behalf Of > > [email protected] <mailto:[email protected]> > > Sent: 01 July 2016 13:07 > > To: [email protected] <mailto:[email protected]> > > Subject: Re: [ceph-users] CEPH Replication > > > > It will put each object on 2 OSD, on 2 separate node All nodes, and > > all OSDs will have the same used space (approx) > > > > If you want to allow both copies of an object to put stored on the > > same node, you should use osd_crush_chooseleaf_type = 0 (see > > > http://docs.ceph.com/docs/master/rados/operations/crush-map/#crush-map-bucket-types > > and > > > > http://docs.ceph.com/docs/hammer/rados/configuration/pool-pg-config-re > > f/) > > > > > > On 01/07/2016 13:49, Ashley Merrick wrote: > > > Hello, > > > > > > Looking at setting up a new CEPH Cluster, starting with the > following. > > > > > > 3 x CEPH OSD Servers > > > > > > Each Server: > > > > > > 20Gbps Network > > > 12 OSD's > > > SSD Journal > > > > > > Looking at running with replication of 2, will there be any issues > > using 3 nodes with a replication of two, this should "technically" > > give me ½ the available total capacity of the 3 node's? > > > > > > Will the CRUSH map automaticly setup each 12 OSD's as a separate > > group, so that the two replicated objects are put on separate OSD > > servers? > > > > > > Thanks, > > > Ashley > > > > > > > > > > > > > > > _______________________________________________ > > > ceph-users mailing list > > > [email protected] <mailto:[email protected]> > > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > > > > _______________________________________________ > > ceph-users mailing list > > [email protected] <mailto:[email protected]> > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > _______________________________________________ > > ceph-users mailing list > > [email protected] <mailto:[email protected]> > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > > > > > > > _______________________________________________ > > ceph-users mailing list > > [email protected] > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > -- > Tomasz Kuzemko > [email protected] > > _______________________________________________ > ceph-users mailing list > [email protected] > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >
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