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

Iozone capps at
Fri Oct 28 23:30:33 GMT 2005

----- Original Message ----- 
From: "Jeremy Allison" <jra at>
To: "Iozone" <capps at>
Cc: <samba-technical at>
Sent: Friday, October 28, 2005 5:59 PM
Subject: Re: Modifying Samba to skip file system reads for IOZONE READ and 

> On Fri, Oct 28, 2005 at 06:03:17PM -0500, Iozone wrote:
>> Dear Richard,
>>         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.


        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 Capps

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