Thanks Georgios for pointing out my mistake: I can still perform reads only because of IO cache on the host .. so the pool really block all requests On 02/24/2018 01:45 PM, Georgios Dimitrakakis wrote: >> The pool will not actually go read only. All read and write requests >> will block until both osds are back up. If I were you, I would use >> min_size=2 and change it to 1 temporarily if needed to do maintenance >> or troubleshooting where down time is not an option. >> >> On Thu, Feb 22, 2018, 5:31 PM Georgios Dimitrakakis wrote: >> >>> All right! Thank you very much Jack! >>> >>> The way I understand this is that its not necessarily a bad >>> thing. I >>> mean as long as it doesnt harm any data or >>> cannot cause any other issue. >>> >>> Unfortunately my scenario consists of only two OSDs therefore >>> there is >>> a replication factor of 2 and min_size=1. >>> >>> What I am trying to figure out is if its more dangerous to have >>> min_size=2 rather than 1 in the above scenario and if it gives me >>> any >>> benefits. >>> >>> I am already aware of the *golden* rule about the minimum number >>> of >>> replicas (3) but the cluster will be reformed soon and until then >>> I >>> would like to know if its better to go with min_size=2 or not. >>> >>> Regards, >>> >>> G. >>> >>> > If min_size == size, a single OSD failure will place your pool >>> read >>> > only >>> > >>> > On 02/22/2018 11:06 PM, Georgios Dimitrakakis wrote: >>> >> Dear all, >>> >> >>> >> I would like to know if there are additional risks when running >>> CEPH >>> >> with "Min Size" equal to "Replicated Size" for a given pool. >>> >> >>> >> What are the drawbacks and what could be go wrong in such a >>> >> scenario? >>> >> >>> >> Best regards, >>> >> >>> >> G. >>> >> _______________________________________________ >>> >> ceph-users mailing list >>> >> ceph-users@xxxxxxxxxxxxxx [1] >>> >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com [2] >>> > >>> > _______________________________________________ >>> > ceph-users mailing list >>> > ceph-users@xxxxxxxxxxxxxx [3] >>> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com [4] >>> >>> _______________________________________________ >>> ceph-users mailing list >>> ceph-users@xxxxxxxxxxxxxx [5] >>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com [6] >> >> >> Links: >> ------ >> [1] mailto:ceph-users@xxxxxxxxxxxxxx >> [2] http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> [3] mailto:ceph-users@xxxxxxxxxxxxxx >> [4] http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> [5] mailto:ceph-users@xxxxxxxxxxxxxx >> [6] http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> [7] mailto:giorgis@xxxxxxxxxxxx > _______________________________________________ > 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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