Hi Warren, Following our brief chat after the Ceph Ops session at the Vancouver summit today, I added a few more notes to the etherpad (https://etherpad.openstack.org/p/YVR-ops-ceph). I wonder whether you'd considered setting up crush layouts so you can have multiple cinder AZs or volume-types that map to a subset of OSDs in your cluster. You'd have them in pools with rep=1 (i.e., no replication). Then have your Hadoop users follow a provisioning pattern that involves attaching volumes from each crush ruleset and building HDFS over them in a manner/topology so as to avoid breaking HDFS for any single underlying OSD failure, assuming regular HDFS replication is used on top. Maybe a pool per HDFS node is the obvious/naive starting point, clearly that implies a certain scale to begin with, but probably works for you...? -- Cheers, ~Blairo _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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