Memory not clearing down.

[Allen Smith]

In unix land unused memory is wasted memory. The system will use it to cache disk pages if nothing else needs it, so it's normal for memory usage to climb over time.

Segfaults (signal 11) are usually a sign of bad memory or some other hardware component. We had a rash of these. Root cause was not enough cooling in the systems causing failed memory and failed power supply's. Added fans, replaced a few power supplies and DIMMS and slowed memory down to 166 from 200 where it didn't matter. Systems are rock solid now.

In our case the building AC turns off on the weekends, so these boxes all worked fine when we got them, but they slowly degraded over the course of 6 months due to the heat of the weekends.

# up2date -i memtest86+
# memtest-setup

Reboot, select memtest from menu and let run for a few hours at least, over the weekend even better.

-Allen

On Friday 20 January 2006 08:44, Andrew.Bridgeman at corusgroup.com wrote:
> 
> We are currently running 30 ish Redhat WS version 3 machines and are having
> a problem with the memory showing 95% used when the machine is idle and not
> being used. I have had this problem in the past but it has never really
> caused a problem but recently we have been getting segmentation errors on
> the machines and i think it is linked to this memory issue.
> 
> Has anyone come across this before? If so how did you fix it? What could i
> do to get it to release memory as soon as things have finished running.
> 
> Any help would be much appreciated.
> 
> Regards
> 
> Andrew Bridgeman