Hi, I was experimenting with Ceph and found an interesting behavior (at least to me) : Number of objects doubled when a new placement group was added. Experiment Set Up: - 3 Nodes with one OSD per node - Replication = 1 - ceph osd pool create $poolName 1; - ceph osd pool set $poolName size 1; - Set number of PG=30 - ceph osd pool set $poolName pg_num 30; - ceph osd pool set $poolName pgp_num 30 - Start creating objects of 1000 Bytes for a period of 120 seconds using rados bench with 1 thread - rados -p $poolName -b 1000 -t 1 bench 120 write &> bench.out - While the creation is going on gather df statistics every second - rados df -p $poolName &> df.out - After 75 seconds add a new placement group - ceph osd pool set $poolName pg_num 31; - ceph osd pool set $poolName pgp_num 31; - Plot the number of objects and data size from the above df command. I was wondering why the number of object count doubled when we add an new placement group. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140514/2ff04930/attachment.htm> -------------- next part -------------- A non-text attachment was scrubbed... Name: object_increase.png Type: image/png Size: 7022 bytes Desc: not available URL: <http://lists.ceph.com/pipermail/ceph-users-ceph.com/attachments/20140514/2ff04930/attachment.png>