[CentOS] CentOS 3 vs. CentOS 4 Memory Utilization

Fri Feb 9 21:43:10 UTC 2007
hkclark at gmail.com <hkclark at gmail.com>

On 2/9/07, Vasiliy Boulytchev <vasiliy at linuxspecial.com> wrote:
> Gents, am I reading this information incorrectly, or is this box also
> swapping about 128M?  Swapping will quickly grind your system to a halt.
>
> I guess this all depends on how many people are connecting to your
> apache servers...  Turn on your server-info and see :)
>
> Vasiliy Boulytchev
> vasiliy at linuxspecial.com
>

Hmmm, now that you mention it, that's a very good point.  Does anyone
out there know why CentOS 3 would swap out so much vs. "giving back
real RAM" from buffers and/or cache?  I agree with Vasiliy that it
looks like the performance on this box could be pretty lame if
anything important is in that swap (I would assume the OS is putting
the "oldest" stuff in swap, but what if an app didn't need to get used
very often and it suddenly received a request... that request could
easily time out while stuff is swapping back in from disk, right?).
Does anyone know a good way to see which app(s) and/or parts of the
OS/libs are being put into swap vs. kept in "real RAM"?

Regards,
KC