[linux-lvm] Re: [Announce] device-mapper beta3 (fast snapshots)

[Joe Thornber]

Andrew,

On Tue, Jul 16, 2002 at 11:05:49AM -0500, Andrew Theurer wrote:
> at 32k all the time?  That would explain why these results are flat, while I
> am getting a wider range.

I think this is a red herring, the chunk size code did accidentally
get backed out of CVS for a while.  But variable chunk sizes were
certainly going into the kernel when we did the development.

> Joe, are you absolutely sure these tests had the disk cache disabled?  That's
> the only hardware thing I can think of that would make a difference.

Absolutely sure.  Those figures were for a pair of PVs that were
sharing an IDE cable so I can certainly get things moving faster.

> It seems we can go 'round and 'round to no end, as long as we have HW
> differences, so I have asked for use on a OSDL system we can both run on.
> This way there is no difference in our HW.  I'll let you know when I hear
> back from them, so we can both test on the same system (if you want to).

Excellent idea, we should probably think up some better benchmarks too.

- Joe