topic Re: Memory staying in cached status in Operating System - Linux

Memory staying in cached status

Andrew Kaplan — Wed, 25 Oct 2006 08:23:24 GMT

Hi there --

I am running Fedora Core 5 that was hardened Bastille Linux on a system with 1.5 GB of RAM. The system functions as an e-mail server running Sendmail along with MailScanner, SpamAssassin, and ClamAV.

I have noticed over time, via the free -m command, that the amount of cached RAM is going up. This results in the amount of free memory going down to where there is almost nothing left. The end result has been the system to periodically hanging, which forces me to reboot the server.

What can I do to correct this problem? Thanks.

Re: Memory staying in cached status

Atul Gautam — Thu, 26 Oct 2006 02:20:48 GMT

Hi Andrew,

Please forward the output for the following commands ---

1) free -m
2) cat /proc/meminfo

Atul

Re: Memory staying in cached status

Patrick Terlisten — Thu, 26 Oct 2006 02:48:27 GMT

Hello Andrew,

are you sure that the amount of free memory is the root cause for your problem? Linux uses free memory as cache. Unused free memory is wasted memory. :) If the amount of free memory is low, Linux will reduce the memory that is used as cache. There is another strange behavior in the memory management: There ist free memory, but the kernel is using swap-space. This behavior is called "swapiness" and can be configured in the /etc/sysctl.conf.

Please check your logs, take a look at /var/log/messages.

Regards,
Patrick