On Sun, Sep 20, 2009 at 6:40 AM, katan <[email protected]> wrote:

> On Sun, 20 Sep 2009 03:03:07 -0400, John Duncan Yoyo wrote:
>
> > Flash drives have a limited number of read write cycles and that might be
> >what you ran into.
>
> I'm not doubting your word, but where do you find this info? and do you
> have any idea what the limit is?
>
> I ask this--maybe I shouldn't admit this in public--because I use a
> thumb drive as my primary data source for email and Quicken. I can use
> it among multiple machines, and if my laptop gets lost/stolen, I don't
> lose anything (nor will it be compromised).**
>

I don't think you need to worry too much if you don't buy the really cheap
stuff and bang on it too hard.  100,000 writes was what was determined to be
necessary to kill a thumb drive by one set of experiments.

This is from the transcript of a Security Now! Episode <
http://www.grc.com/sn/SN-063.htm>.   I haven't spent any time further
exploring it but I filed it away when I heard it three years ago.

*Steve:* Well, you are. But the way Windows operates � first of all, Flash
reads at about twice the speed that it writes. Another concern is that Flash
has a write limit. The actual chemical technology of the non-volatility of a
Flash has a maximum of about 100,000 write cycles. So, for example, people
who arrange, like, Flash-booting Linux systems, in fact I have myself a
Flash-booting FreeBSD system that I built, I had to go to some lengths to
not have a swapping partition on the Flash. And in fact, to make sure that I
was mounting my Flash partitions in read-only mode, so that the system would
be logging to RAM and to Flash, because you never want a situation where by
default you're writing often and hard to your Flash because it will
end-of-life that device very quickly. Mark Thompson actually did some
experiments where he burned out a Flash in a couple of�days...

*Leo:* Wow.
*Steve:* ...just by booting a standard Windows system. And Windows just
thrashed the thing and killed it. And...
-- 
John Duncan Yoyo
-------------------------------o)


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