Hi, my goal is to set the 'object size' used in the distribution inside rados in an equal (or similar) way between RBD and CephFS. To set obj_size=64k in RBD I use the command: rbd create --size 1024000 --pool SSD-r2 ssd2-1T-64k --order 16 On cephfs set_layout '-s 65536' runs into EINVAL: cephfs /mnt/cephfs/fio-64k/ set_layout -p 3 -s 65536 -u 4194304 -c 1 Error setting layout: Invalid argument cephfs /mnt/cephfs/fio-64k/ set_layout -p 3 -s 65536 -u 65536 -c 1 cephfs /mnt/cephfs/fio-64k/ show_layout layout.data_pool: 3 layout.object_size: 65536 layout.stripe_unit: 65536 layout.stripe_count: 1 The man page of cephfs says ---snip--- -u --stripe_unit Set the size of each stripe -c --stripe_count Set the number of objects to stripe across -s --object_size Set the size of the objects to stripe across ---snip--- What is the equivalent command on cephfs to 'rbd create --order 16' ? Can you please give same explanation how "--stripe_unit --stripe_count --object_size" should be used in combination to achieve different layouts on CephFS directories (e.g. optimized for streaming, small sequential IOs, small random IOs) ? Thanks, -Dieter -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html