Re: how can a bit be off in memory?

Robert M. Riches Jr. wrote:
On 2007-06-29, Charles T. Smith <cts.private@xxxxxxxxx> wrote:
Vim started crashing on me, particularly when I tried to open new lines.
I finally checked it out with rpm and a newly downloaded copy of vim's
rpm and discovered that exactly one byte, deep into vim, was wrong.

I rebooted my machine (which has been super-solid for years) - and the
difference was gone.

So, what are the opinions - did I run into a hardware glich, or was
there a freaky issue with memory mapping?

If rebooting the machine made the (apparent) error go away,
then my guess would be a bit got flipped in RAM, the page of
RAM that held the cached copy of the page from disk. While
I worked at a large chip company, I heard of cosmic rays,
alpha particles, and such causing occasional soft errors in
RAM. (That's why ECC RAM was a primary factor in the
motherboard I chose when I built my machines.) I would
suggest running memtest86 overnight to check for something
more sinister.

How would an alpha particle (helium nucleus) get through a computer case and
through the plastic of a RAM chip? How could even a beta ray (electrons) get
through a metal case? The only thing I would expect to cause problems would
be gamma rays (cosmic rays). You might as well have ECC RAM (I do).

--
.~. Jean-David Beyer Registered Linux User 85642.
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.

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