> If following the "raid mirror" approach, would you then skip redundency > at the ceph layer to keep your total overhead the same? It seems that > would be risky in the even you loose your storage server with the > raid-1'd drives. No Ceph level redunancy would then be fatal. But if > you do raid-1 plus ceph redundancy, doesn't that mean it takes 4TB for > each 1 real TB? >
Depends on your replication settings. Maybe if you originally wanted 3 replica's, you might decide that because you are now using RAID1, 2 replicas is sufficient, so you have gone from 3x to 4x in terms of raw storage vs useable storage. Disks fail more than entire nodes, so depending on your requirements, a 33% increase in storage may be a reasonable tradeoff. James _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
