[Samba] Re: How Samba let us down

[Richard Sharpe]

On Wed, 23 Oct 2002, Jay Ts wrote:

> Esh, Andrew wrote:
> > Here at Tricord, we run Samba through some pretty intense tests, as well.
> > Since we are a file system producer, we focus on corruption bugs. We haven't
> > found any in Samba,
> 
> Since I've been curious about this anyway, I might go ahead and check:
> 
> Do you (And J. Terpstra, and others) test sending really huge files,
> such as 700 MB ISO CD-ROM images or bigger, across the net, and then
> run a cmp on them, going in each direction.  That is:
> 
> 1. Start with a reference huge file on Windows, known to match an
>    existing file on Unix, then copy it over through Samba and
>    do a cmp on them?  About how many times is this done in your
>    tests?  More than a few hundred?
> 
> 2. Also run the test the other way, and compare the copies on
>    the Windows side?

In my opinion, while it is possible to do what you say, that is not how
you will detect corruption. Corruption of the sort you mention will be
detected very quickly in normal tests.

The sort of corruption I think we should check for is the following:

1. Samba getting confused when one user has multiple files open and writes
to different files in quick succession.

2. Multiple samba clients having files open and the file system getting
confused and mixing up writes from different users.

cifs-load-gen would be an ideal tool for testing this if it is extended in
a couple of ways. I have started talking to JHT about this.

BTW, Tridge has already written a file system stress tester, as have
others, that can detect the second sort of corruption.

Regards
-------
rsharpe at ns.aus.com, www.richardsharpe.com,
sharpe at samba.org, sharpe at ethereal.com