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

[Szabolcs Szakacsits <szaka@ntfs-3g.org>]

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

	Szaka

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