Re: Test results for ext4

["Jose R. Santos" <jrs@us.ibm.com>]

On Mon, 02 Jun 2008 15:44:04 +0200
Valerie Clement <valerie.clement@bull.net> wrote:

> Jose R. Santos wrote:
> >         agefs=1
> >         [threadgroup0]
> >                 num_threads=10
> >                 write_size=40960
> >                 write_blocksize=4096
> >                 create_weight=10
> >                 append_weight=10
> >                 delete_weight=1
> >         [end0]
> >                 desired_util=0.80
> > 
> > This will age the filesystem until it reaches 80% utilization before
> > starting the benchmark.  Since a 5TB disk will take a while to age,
> > I suggest trying this on just a few runs.
> Ok to do it only on a few runs (creating a 4TB file on my device takes
> more than 12 hours...)
>    Valérie

Wow...

Maybe running aging on a 5TB fs is not such a good idea.  I think it
would be better to run it on a smaller array size (1TB maybe).  I
suspect that one of the reasons this is taking so long is that with 4TB
of small files, the rbtree in FFSB would be huge and could be larger
than the 2GB of memory you are running on your system, causing you to
swap.


Running on a smaller FS should still give a good idea of how well the
filesystems avoid fragmentation.


-JRS
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html