[Beowulf] VMC - Virtual Machine Console

Peter Skomoroch peter.skomoroch at gmail.com
Fri Mar 7 09:05:03 PST 2008


Joe, thanks for the feedback.  The bonnie results were not actually mine, I
was just pointing to some numbers run by Paul Moen.

Your 1GB file data is likely more representative, but with 15 GB ram,
> you need to be testing 30-60 GB files.
>

I'll try to tweak the BPS bonnie tests to run some large files...


On Fri, Mar 7, 2008 at 11:57 AM, Joe Landman <
landman at scalableinformatics.com> wrote:

> Peter Skomoroch wrote:
>
> > Extra Large Instance:
> >
> >       15 GB memory
> >       8 EC2 Compute Units (4 virtual cores with 2 EC2 Compute Units
> each)
> >       1,690 GB instance storage (4 x 420 GB plus 10 GB root partition)
> >       64-bit platform
> >       I/O Performance: High
>
> Note:  minor criticism, but overall, nice results.
>
> Looking over your bonnie results is worth a quick comment.  Any time you
> have bonnie or IOzone (or other IO benchmarks) which are testing file
> sizes less than ram size, you are not actually measuring disk IO.  This
> is cache speed pure and simple.  Either page/buffer cache, or RAID
> cache, or whatever.
>
> We have had people tell us to our face that their 2GB file results (on a
> 16 GB RAM machine) were somehow indicative of real file performance,
> when, if they walked over to the units they were testing, they would
> have noticed the HD lights simply not blinking ...  Yeah, an amusing
> beer story (the longer version of it), but a problem none-the-less.
>
> Your 1GB file data is likely more representative, but with 15 GB ram,
> you need to be testing 30-60 GB files.
>
> Not trying to be a marketing guy here or anything like that ... we test
> our JackRabbit units with 80GB to 1.3TB sized files.  We see (sustained)
> 750 MB/s - 1.3 GB/s in these tests.  We also note some serious issues
> with the linux buffer cache and multiple RAID controllers (buffer cache
> appears to serialize access).  We do this as we actually want to measure
> disk performance, and not buffer cache performance.
>
> That criticism aside, nice results.  It shows what a "cloud" can do.
>
> >       Price: $0.80 per instance hour
>
>
> --
> Joseph Landman, Ph.D
> Founder and CEO
> Scalable Informatics LLC,
> email: landman at scalableinformatics.com
> web  : http://www.scalableinformatics.com
>        http://jackrabbit.scalableinformatics.com
> phone: +1 734 786 8423
> fax  : +1 866 888 3112
> cell : +1 734 612 4615
>



-- 
Peter N. Skomoroch
peter.skomoroch at gmail.com
http://www.datawrangling.com
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