Best practice for production servers: To reboot or not to reboot?

[richard.pieri-Re5JQEeQqe8AvxtiuMwx3w at public.gmane.org (Richard Pieri)]

On Sep 14, 2010, at 5:04 PM, Derek Martin wrote:
> 
> Yeah except that's not what gaf meant, which was fairly clear from
> context, which is why what you said made no sense.  He was talking
> about memory management, where VM clearly means virtual memory, and
> virtual machine is not especially interesting or relevant.

Whereas I was explicitly writing about application memory fragmentation, where VM clearly means virtual machine:
> What Jack said about applications.  Even though an application doesn't leak memory it can still suffer from memory fragmentation which will eventually degrade performance.


Virtual memory is entirely irrelevant.

> Really?  I've never heard of any such issues causing sweeping problems
> in the sysadmin community...  You'd think that if the Linux kernel
> had "been *very* vulnerable to memory fragmentation issues" you'd have
> heard all sorts of reports about wide spread system crashes.  Methinks
> you overstate the case by rather a lot.

Memory fragmentation does not result in system crashes.  Never has.  It does cause performance degradation, which I explicitly stated.  Here's some useful information about it and what some recent kernels do about it:
http://lwn.net/Articles/211505/

--Rich P.