Modifying Samba to skip file system reads for IOZONE READ and REREAD

[Richard Sharpe]

On Fri, 28 Oct 2005, Iozone wrote:

>>>         The new version of Iozone will become available within the
>>>     next 24 hours on the Iozone web site. This version will
>>>     disable your, un-ethical, hack. Please take a few moments
>>>     of introspection and ponder of the value of honesty to
>>>     the public. There is no real value in providing mechanisms
>>>     that tell lies to the consumer.
>> 
>> Can you explain more about this post ? I don't think I've understood
>> what has been going on here ?
>> 
>> Thanks,
>> 
>> Jeremy Allison,
>> Samba Team.
>> 
>
> Jeremy,
>
>       Iozone measures a filesystem's performance by writing and
>   reading files. Mr. Sharpe, provided a hack in Samba that
>   detects when Iozone is running. (keying off of the file names
>   that Iozone uses)  This hack intercepts the user's reading
>   of a file, detects that it is Iozone running, and then
>   allocates buffers and fills them in with what it knows
>   Iozone wants. Thus, the user's reads NEVER made it
>   to the filesystem at all, and the results reported by
>   Iozone will not reflect the filesystem, but a deliberate
>   HACK, specifically targeted towards circumventing
>   accurate measurement by Iozone. Thus, telling the user
>   lies. These lies will NOT reflect any other application
>   running and will only mislead the consumer into believing
>   that the system is fast, when in reality it may suck big-time !
>
>       Richard's code is NOT cool. It is a deliberate attempt
>   to tell the users of Samba LIES. IT IS NOT COOL !
>
>       I have immediately modified Iozone so that Richard's
>   hack will not work, and in fact, will now only serve to
>   demonstrate that Samba is broken, and returning the
>   WRONG data from a file that was just written.
>       Iozone will change the contents of its data files with every
>   new version. Any attempt to try this sort of *&&%&% again
>   will result in Iozone telling the user that Samba is broken
>   and should not be used for storing data.
>
>   Richard: Your hack is NOT in the interest of honesty
>                 or beneficial to the public. It is just plain evil.

Don,

I have always found your help in the past to be very useful, but I fear 
you have over-reacted to something that was intended to help people debug 
performance issues.

I have already responded to an earlier message, and did so before seeing 
this response. However, I feel that I must respond.

Did you think about what you were typing before making claims that I am an 
unethical person?

Perhaps if you had sent me a short email asking me what my intent was 
before making outrageous public claims we could have dealt with the issue 
in a more reasonable manner.

For the record, I agree that people should not be able to defeat 
benchmarking programs like IOZONE and so forth.

Regards
-------
Richard Sharpe, rsharpe[at]richardsharpe.com, rsharpe[at]samba.org,
sharpe[at]ethereal.com, http://www.richardsharpe.com