[CentOS] pagecache corruption on Tyan S3870

What you should be doing, is swapping the CPUs and ram modules from
board to board.
With the help of someone who can do some statistical analysis for you,
you can quickly pinpoint whether the problem resides in the
motherboards, or some CPUs or ram modules, or combinations thereof.

Presumably, since the servers are so prone to error at the moment, they
will not be doing anything important, allowing you to easily swap stuff
around.
If you can include in this trial, some identical servers which seem to
be working fine, this will greatly speed up the process of apportioning
blame.