hi i tried to change data "max_size" to 1 to disable replication for testing. what i've done (reproducable): mkcephfs -c /etc/ceph/ceph.conf --mkbtrfs (1mds, 1mon, 2osd (2 phyiscal disks)) start ceph mount ceph fs write some files to the mount ceph osd getcrushmap -o /tmp/crush crushtool -d /tmp/crush -o /tmp/crush.txt change data "max_size 10" to "max_size 1" in /tmp/crush.txt crushtool -c /tmp/crush.txt -o /tmp/crush.new ceph osd setcrushmap -i /tmp/crush.new (Output: * read 428 bytes from /tmp/crush.new * 10.06.16_08:12:57.187556 41223950 monclient(hunting): found mon0 * 10.06.16_08:12:57.188298 mon <- [osd,setcrushmap] * 10.06.16_08:12:58.303241 mon0 -> 'set crush map' (0) ) after starting to write a file to the mount, I see these kernel messages : http://pastebin.com/maVj9daV ceph / kclient are yesterdays git unstable / unstable-backport versions. kernel is debian lenny backport 2.6.32. - Thomas -- 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