Re: [PATCH RFC] nilfs2: continuous snapshotting file system

[Andrew Morton <akpm@linux-foundation.org>]

On Thu, 21 Aug 2008 00:25:55 +0300 (MET DST)
Szabolcs Szakacsits <szaka@ntfs-3g.org> wrote:

> 
> On Thu, 21 Aug 2008, Ryusuke Konishi wrote:
> > >> Some impressive benchmark results on SSD are shown in [3],
> > >
> > >heh.  It wipes the floor with everything, including btrfs.
> 
> It seems the benchmark was done over half year ago. It's questionable how 
> relevant today the performance comparison is with actively developed file 
> systems ...
> 
> > >But a log-based fs will do that, initially.  What will the performace
> > >look like after a month or two's usage?
> > 
> > I'm using NILFS2 for my home directory for serveral months, but so far
> > I don't feel notable performance degradation. 
> 
> I ran compilebench on kernel 2.6.26 with freshly formatted volumes. 
> The behavior of NILFS2 was interesting.
> 
> Its peformance rapidly degrades to the lowest ever measured level 
> (< 1 MB/s) but after a while it recovers and gives consistent numbers.
> However it's still very far from the current unstable btrfs performance. 
> The results are reproducible.
> 
>                     MB/s    Runtime (s)
>                    -----    -----------
>   btrfs unstable   17.09        572
>   ext3             13.24        877
>   btrfs 0.16       12.33        793
>   nilfs2 2nd+ runs 11.29        674
>   ntfs-3g           8.55        865
>   reiserfs          8.38        966
>   nilfs2 1st run    4.95       3800
>   xfs               1.88       3901

err, what the heck happened to xfs?  Is this usual?