From: "Arnab Ganguly" [EMAIL PROTECTED]
> >It up to the OS to mark the freed areas as free or use it as a
> >filesystem buffer or whatever buffer, as long as the memory isn't needed
> >by applications.
>
> Thanks for the update.Actually when I do top -p on the process id I do see
> memory consumed by Apache is very less but over the time when I do free -m
> the RAM gets reduced.
As Robert indicated, a running Linux system will attempt to make use of all
physical memory. This is because it is undesirable to leave memory unused
(wasted) when it can be put to good use for things such as disk cache.
Google "linux memory management" for more information.
> I wonder can be this case happen free -m is 0 and the
> machine will crash or something....
Typically, you will see free memory get close to 0 and stay there. It will
usually not go past that point unless you have your machine overloaded in some
fashion. In most cases, even if free memory dips to 0, you will still have
your swap memory available. At that point, system performance will start to
degrade, but you will still be running.
> I was thinking may be the Apache was eating up the RAM
To see how much physical memory (in kilobytes) is being used by Apache, use
this command sequence:
ps -e -o rss,comm | fgrep httpd | awk '{sum+=$1} END {print sum}'
It is not unusual to see memory go up as an Apache process matures. This is
especially true if you are running modules like PHP or Perl which have the
potential to load many helper modules. A quick review of a handful of running
machines available to me show 2-18MB per process is not unusual. Of those, PHP
users are typically 10-12MB higher than non-PHP users. YMMV.
Regards,
Chris Kukuchka
Sequoia Group, Inc.
