2011/10/26 Sage Weil <sage@xxxxxxxxxxxx>: > On Wed, 26 Oct 2011, Christian Brunner wrote: >> >> > Christian, have you tweaked those settings in your ceph.conf? It would be >> >> > something like 'journal dio = false'. If not, can you verify that >> >> > directio shows true when the journal is initialized from your osd log? >> >> > E.g., >> >> > >> >> > 2011-10-21 15:21:02.026789 7ff7e5c54720 journal _open dev/osd0.journal fd 14: 104857600 bytes, block size 4096 bytes, directio = 1 >> >> > >> >> > If directio = 1 for you, something else funky is causing those >> >> > blkdev_fsync's... >> >> >> >> I've looked it up in the logs - directio is 1: >> >> >> >> Oct 25 17:20:16 os00 osd.000[1696]: 7f0016841740 journal _open >> >> /dev/vg01/lv_osd_journal_0 fd 15: 17179869184 bytes, block size 4096 >> >> bytes, directio = 1 >> > >> > Do you mind capturing an strace? I'd like to see where that blkdev_fsync >> > is coming from. >> >> Here is an strace. I can see a lot of sync_file_range operations. > > Yeah, these all look like the flusher thread, and shouldn't be hitting > blkdev_fsync. Can you confirm that with > > filestore flusher = false > filestore sync flush = false > > you get no sync_file_range at all? I wonder if this is also perf lying > about the call chain. Yes, setting this makes the sync_file_range calls go away. Is it safe to use these settings with "filestore btrfs snap = 0"? 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
