[ale] How to stress test flash memory

[Greg Freemyer]

On Sat, Nov 27, 2010 at 1:17 PM, Richard Bronosky <Richard at bronosky.com> wrote:
> I just bought a cheap CF card from the clearance isle at the PX. I'd
> lke to test the thing for "bad sectors" before I put it to use. I only
> have access to Mac and Linux. I could script something in bash, but I
> figure there has to be a trusted tool for this. Please advise.
>
> --
> .!# RichardBronosky #!.

What's your goal?

AFAIK, CF cards typically use a logical to physical mapping that
basically causes the map to update on every write to the ERASE block
(typically 128KB).

So it would be hard to track bad physical sectors if all you know is
the logical sector.  I guess if you know a specific physical sector is
bad you could ensure you never write to that entire ERASE block, then
you would be okay.

But that would mean knowing how the erase blocks are aligned, and then
marking every sector in the erase block (all 256 of them) as bad.

If on the other hand you are doing this as part of a QA process and
will simply reject / discard CF cards that show failure, then doing
something like describe makes sense.

Greg