On 17 February 2016 at 14:59, Christian Balzer <chibi@xxxxxxx> wrote: > > Hello, > > On Wed, 17 Feb 2016 13:44:17 +0000 Ed Rowley wrote: > >> On 17 February 2016 at 12:04, Christian Balzer <chibi@xxxxxxx> wrote: >> > >> > Hello, >> > >> > On Wed, 17 Feb 2016 11:18:40 +0000 Ed Rowley wrote: >> > >> >> Hi, >> >> >> >> We have been running Ceph in production for a few months and looking >> >> at our first big expansion. We are going to be adding 8 new OSDs >> >> across 3 hosts to our current cluster of 13 OSD across 5 hosts. We >> >> obviously want to minimize the amount of disruption this is going to >> >> cause but we are unsure about the impact on the crush map as we add >> >> each OSD. >> >> >> > So you are adding new hosts as well? >> > >> >> Yes, we are adding 2 new hosts with 3 OSDs and adding two drives/OSDs >> to an existing host >> > Nods. > >> >> From the docs I can see that an OSD is added as 'in' and 'down' and >> >> wont get objects until the OSD service has started. But what happens >> >> to the crushmap while the OSD is 'down', is it recalculated? are >> >> objects misplaced and moved on the existing cluster? >> >> >> > Yes, even more so when adding hosts (well, the first OSD on a new >> > host). >> > >> > Find my "Storage node refurbishing, a "freeze" OSD feature would be >> > nice" thread in the ML archives. >> > >> > Christian >> > >> >> Thanks for the reference, the thread is useful, >> >> I am right with the assumption that adding an OSD with: >> >> [osd] >> osd_crush_initial_weight = 0 >> > Or by adding it with a weight of zero like this: > > ceph osd crush add <osdnumber> 0 host=<osdhost> > Thanks, we will give it a try. >> will not change the existing crush map >> > Well it will change it (ceph osd tree will show it), but no data movement > will result from it, yes. > > Christian >> >> >> We think we would like to limit the rebuild of the crush map, is this >> >> possible or beneficial. >> >> >> >> Thanks, >> >> >> >> Ed Rowley >> >> _______________________________________________ >> >> ceph-users mailing list >> >> ceph-users@xxxxxxxxxxxxxx >> >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> >> >> > >> > >> > -- >> > Christian Balzer Network/Systems Engineer >> > chibi@xxxxxxx Global OnLine Japan/Rakuten Communications >> > http://www.gol.com/ >> >> Regards, >> >> Ed Rowley >> > > > -- > Christian Balzer Network/Systems Engineer > chibi@xxxxxxx Global OnLine Japan/Rakuten Communications > http://www.gol.com/ Regards, Ed Rowley _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |