When I check /proc/diskstats on mounted partitions before and after 'sync' on idle system, I can tell from write activity which partitions are btrfs and which are ext3/ext4/swap.
On idle system after running sync, there is no activity on any ext3/ext4/swap except root filesystem. But there are writes on all btrfs filesystems. Without 'sync' command btrfs behave well, and there is no read/write activity on idle system to distinguish from ext4. for example some btrfs and ext4 partition before and after sync: # grep -P "dm-10|dm-6" /proc/diskstats 253 10 dm-10 477158 0 26422280 33602927 2721495 0 26556408 216043746 0 7504653 249648820 253 6 dm-6 11958 0 618266 431644 3315 0 26520 27535 0 147647 459184 # sync # grep -P "dm-10|dm-6" /proc/diskstats 253 10 dm-10 477158 0 26422280 33602927 2721724 0 26558408 216050353 0 7504999 249655428 253 6 dm-6 11958 0 618266 431644 3315 0 26520 27535 0 147647 459184 in summary: Field 5 -- # of writes completed increased from 2721495 to 2721724 (total 229 writes) Field 7 -- # of sectors written increased from 26556408 to 26558408 (total 2000 sectors) Field 8 -- # of milliseconds spent writing increased from 216043746 to 216050353 (total 6607 milliseconds) and this repeats after each 'sync' with similar totals My system is Fedora 15 kernel 2.6.40.3-2.fc15.i686.PAE (this is should be 3.0.3 with some Fedora patches) Thanks Roman Kapusta -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
