On Wed, Mar 14, 2018 at 09:50:12PM +0100, mart.v wrote: : But from what I understood so far, during the writing process the : client communicates also only with the primary OSDs but it will wait : until all data are written on all replicas. This is my main concern. : Does this mean that writing speed (and IOps) will be limited by the : slowest HDD? Yes that is true. So if you only (or mostly) care about read performance your plan may be advantageous, but if write performance is important you will be sad. Using SSD WAL+DB in front of the spinning disk Data for bluestore (or SSD journals + HDD filesystems for filestore) can help juice write performance to an extent. To what extent is an important but AFAIK unanswered question. -Jon _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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