Hi, you can reduce reserved space for ext4 via tune2fs and gain a little more space, up to 5%. By the way, if you are using Centos7, it reserves ridiculously high disk percentage for ext4 (at least during instalation). Performance probably should be compared on smaller allocsize mount option for xfs (32..512k) and comparison should be made for long runs (like weeks of small writes from a bunch of clients to reach bad enough fragmentation ratio). When I measured comparable results last time, it was a bobtail era, and XFS started to decrease operation speed on about 40% of real allocation. If you prefer to use rados bench, real-life fragmentation may be achieved by running multiple benches with small block size simultaneously in different pools over same set of OSDs. _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com