Reading the latest pull request by Chris Mason, I was wondering about the recommended mount options for an OSD-Filesystem. In the past I came across the following btrfs options, that were used in conjunction with ceph: - nodatacow: To avoid fragmentation. I think this one makes sense when you are using rbd, but it turns of btrfs-csums. Is it safe to use? (ceph has his own csums, right?) - autodefrag: To reduce fragmentation. I think this one makes sense in any case. - compression: I'm using lzo compression right now, as my CPUs in the OSD nodes where idle most of the time and it is improving throughput quite a bit. - notreelog: Never heard of it before I read the pull request. Should I use it? - flushoncommit: Is it obsolete now? - nocluster (requires an additional btrfs patch from Alexandre): I was reading that he was able to reduce the excessive metadata overhead, but it is slower. Does anyone know more about it? I'm running with "noatime,compression=lzo" at the moment, but I'm planning to add autodefrag as soon as my load problems are fixed. I would really like to know, what you are using and why? Thanks, Christian -- 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
