2012/3/1 Chris Mason <chris.mason@xxxxxxxxxx>: > On Thu, Mar 01, 2012 at 03:03:53PM +0100, Jacek Luczak wrote: >> 2012/3/1 Hillf Danton <dhillf@xxxxxxxxx>: >> > On Thu, Mar 1, 2012 at 9:35 PM, Jacek Luczak <difrost.kernel@xxxxxxxxx> wrote: >> >> >> >> While I was about to grab acp I've noticed seekwatcher with made my day :) >> >> >> >> seekwatcher run of tar cf to eliminate writes (all done on 3.2.7): >> >> 1) btrfs: http://dozzie.jarowit.net/~dozzie/luczajac/tar_btrfs.png >> >> 2) ext4: http://dozzie.jarowit.net/~dozzie/luczajac/tar_ext4.png >> >> 3) both merged: http://dozzie.jarowit.net/~dozzie/luczajac/tar_btrfs_ext4.png > > Whoa, seekwatcher makes it pretty clear. Yep, ext4 is close to my wife's closet. >> >> >> >> I will send acp results soon. >> >> >> > Would you please take reiserfs into account? >> >> As of now not (lack of time) but I'm pretty close to consider XFS in >> the game. Whenever I will have more time and there won't be a pressure >> on giving host back to production I will redo same tests for reiserfs. >> >> Now I'm focused on the userspace sorting results. > > reiserfs should have results very similar to ext4. The directory > hashing used by reiserfs is going to result in a very random read > pattern. > > XFS will probably beat btrfs in this test. Their directory indexes > reflect on disk layout very well. True, but not that fast on small files. Except the question I've raised in first mail there's a point in all those action. We are maintaining host that are used for building software: random access, lot of small files and dirs (always a co), heavy parallel IO. We were testing XFS vs ext4 a year ago and XFS was around 10% slower on build times. We did not - yet - done same on btrfs. Now we're looking for replacement for ext4 as we suffer from those issue - but we were not aware of that until stepped into this issue. If you would like me to do some specific tests around ext4 and btrfs, let me know. -Jacek -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
