I''ve been testing (using) btrfs for a little while and noticed some performance issues a couple months ago whenever I called sync(2). After some googling it seem some other people have had similar issues: http://comments.gmane.org/gmane.comp.file-systems.btrfs/13511 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/601299 The odd part for me was that it seemed to work reasonably well at first but then it got progressively worse until I reboot. I ended up writing a quick program that runs `sync(); sleep(60);'' in a loop to record the time spent in each call to sync(). This was with an older kernel, but you can see how it got worse over several days and never really recovered: http://andy753421.ath.cx/linked/btrfs/btrfs-sync-3.2.0-rc1.png I updated my kernel after that to the latest stable version at the time, 3.2.6, and started recording data again. With the new version, most of the problems seemed to go away (thank you!), but the graph still looks a little odd to me so I''m posting here anyway :) http://andy753421.ath.cx/linked/btrfs/btrfs-sync-3.2.6.png To me, the strangest part seems to be the bump around days 4-6. I remember what happened there too. At around 4 days I ran an apt-get update which caused the initial spike, then when that finished the sync times where around 3 seconds as opposed to the 1.5s before. Then at 6 days I ran apt-get update again, but when that finished the sync times went back down to 1.5 seconds! I tried it again a day later, but couldn''t reproduce the 3 second bump in sync times.. After that it seems to gets slowly slower for a while, but nothing quite as strange as the 3 second bump around days 4-5. For reference, this is running on a Core 2 Quad with 2GB of ram. Btrfs is running on a raid 5 array of 3 1TB disks. I''ve included the sections of /etc/fstab and df -h for all my mounted partitions as well. I''ve had btrfs running on a laptop as well, but didn''t notice any issues there. Could it be something to do with the raid array? Any other thoughts on what could cause this, or should I just assume it''s normal and ignore it? :) /etc/fstab: /dev/md3 / btrfs noatime 0 1 /dev/md4 /mnt/x btrfs noatime 0 0 /dev/sdd4 /mnt/backup reiserfs noatime 0 0 df -h: Filesystem Size Used Avail Use% Mounted on rootfs 80G 16G 59G 21% / /dev/root 80G 16G 59G 21% / /dev/md4 1.8T 1.4T 330G 82% /mnt/x /dev/sdd4 313G 177G 137G 57% /mnt/backup -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html