I have been testing osd on btrfs, and the first thing I notice is that there is constant write activity when idle. The write activity hovers between 5Mbytes/second and 30Mbytes/second, and averages around 9Mbytes/second (as determined by iostat -x 30). On average, iostat is showing around 90 w/s, and 25% util. There were two OSD's on this server running btrfs and both were behaving like this. I changed one back to xfs last night and it's not showing any write activity at idle now. There is no matching write activity on the journal device, but the high writes stop when I kill the OSD process. kworker, ceph-osd, and btrfs-cleaner processes feature highly in iotop Is this normal? And is it a problem, or just btrfs doing background writes for some reason? I'm running dumpling on Debian, fwiw. Thanks James _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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