On Tue, May 8, 2012 at 8:39 AM, Nick Bartos <nick@xxxxxxxxxxxxxxx> wrote: > I am considering converting some OSDs to xfs (currently running btrfs) > for stability reasons. I have a couple of ideas for doing this, and > was hoping to get some comments: > > Method #1: > 1. Check cluster health and make sure data on a specific OSD is > replicated elsewhere. > 2. Bring down the OSD > 3. Reformat it to xfs > 4. Restart OSD > 5. Repeat 1-4 until all btrfs OSDs have been converted. ... > Obviously #1 seems much more appetizing, but unfortunately I can't > seem to find out how to verify that data on a specific OSD is > replicated elsewhere. I could go off general cluster health, but that > seems more error prone. You can set the osd weight in crush to 0 and wait for the files inside the osd data dir to disappear. If you want to control how much bandwidth is consumed for this transfer, you can also drop the weight in e.g. 0.1 decrements. That should give you enough feedback from "du" or "df" to be comfortable with the fact that your data is actually moving elsewhere. I'd recommend completely removing the osd, and creating a new one; you can even reuse the the osd id. Just don't try to copy the files over from filesystem to another; the details of the btrfs interaction are more low-level than what just a tar or cp can capture. -- 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
