Amount of memory still going down.

[Will McDonald]

On 14/02/06, Will McDonald <wmcdonald at gmail.com> wrote:
> On 14/02/06, Andrew.Bridgeman at corusgroup.com
> <Andrew.Bridgeman at corusgroup.com> wrote:
> >
> >
> > I have had a problem on our Redhat Version 3 servers for a while now and i
> > have been unable to find out what the issue is. Basically when we reboot
> > our servers, within two weeks the memory used on the servers is 3.2gig so
> > we only have 350 mega bytes of memory left and it is still decreasing by
> > the day. I cannot see any processes that are causing this issue. Below is
> > what i get with the top command, How do i identify the problem, has anyone
> > seen this before and how was it resolved without rebooting the machines
> > every 3 -4 weeks.
>
> The kernel will use up all available RAM over time as efficiently as
> possible so seeing a system using the majority of its memory isn't
> necessarily something to worry about.
>
> http://www.puschitz.com/TuningLinuxForOracle.shtml#CheckingPhysicalMemory
>
> "Linux tries to use all the memory for disk buffers and cache. It
> helps the system to run faster because disk information is already in
> memory and Linux doesn't have to read it from disk again. If space is
> needed by a program or application like Oracle, Linux will make the
> space available immediately. So if your system runs for a while, you
> will usually see a small number for "free" in the first line, and
> there is nothing to be worried about."

Actually, I should probably add, that this is nothing to worry about
as long as the system's not swapping excessively (where "excessively"
usually equates to "at all" :))

Run "vmstat 5" and watch the ---swap-- column's si/so values. As long
as those remain 0 / 0 most of the time you're OK.

Will.