Probably not. However, a contemplation...
It's like a plane. Planes can have 1 engine, or 2, or even more, but
usually not more than 4. Why not 8 engines? 100?
Plane engines have two failure modes:
1) they stop working. If that engine is all you got, you're in deep
doodoo. That's why an extra engine is convenient.
2) The engine explodes, taking the plane with it (fortunately, much
less likely).
If you have multiple engines, you reduce the chance of a crash
because of failure 1, but you increase the chance of a crash in case
of failure 2. So there's a balance to be found.
There is another problem with multiple engines. If you have, say, 4
engines, the plane will be heavier and part of the power of engines
will be used just to carry redundant engines.
Back to virus scanners, adding more virus scanners means more CPU
cycles will be needed, scanning will take longer, ...
The same goes for virus scanners. Failure mode 1 would be a virus
scanner not detecting a virus. Failure mode 2 (less likely) would be
a false positive, or worse, an exploit causing your server to be hacked.
Personally, I find two or three virus scanners to be the sweet spot.
If programmed correctly, it even gives you some protection against
false positives, because you can treat files/emails that are only
recognized by one scanner differently from the ones that are
recognized by multiple scanners. For example quarantine in the first
case, and remove in the second case. (This requires custom
programming, of course).
And another consideration is the reason for running them. If, like me,
you are running them to reduce the likelihood of spreading malware, I
run only one scanning agent. If you are running them to protect your
corporate environment, then the more the merrier with consideration of
server loading.
--
Jim Preston
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