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 majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to