How to reduce "Cached" memory on RHEL 3?

[Jack Fan]

All,
How to reduce the "Cached" memory on RHEL3? My server installed 4GB main memory, but the "cached" memory alway shows 2.3GB on top. So the memory utilization always 99%.

Thanks,
Jack Fan

[Mike Stroyan]

You should decide and tell us why you want to reduce the "Cached" memory.

"Cached" memory is kept cached because it is easily freed, but is expected to be more useful as a page cache than as free memory.

Do you want to keep it low because you want it to be available? It is available for reallocation.

Do you want to drive it low to make file operations start from having no cached memory for a benchmark?

There is a pagecache limit in RHEL 3 that can be set by writing to /proc/sys/vm/pagecache
as described in /usr/src/linux*/Documentation/sysctl/vm.txt .
That has a minimum, goal, and maximum percentage of memory to use for pagecache.

[dirk dierickx]

it's not a problem, linux will manage your memory just fine and free up whatever it needs to free when it is required.

[Vitaly Karasik_1]

Jack, you can read this thread for linux virtual memory discussion http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=1029490

[Atul Gautam]

Hi Jack,

You can also check and change the parameters in "/proc/meminfo" file but check out if those settings persist if the server reboots........

Also, the directory "/proc/sys/vm" has got a no. of files to change the settings.



--
Atul

[Atul Gautam]

Hi Jack,

You can also check and change the parameters in "/proc/meminfo" file but check out if those settings persist after server gets rebooted........

Also, the directory "/proc/sys/vm" has got a no. of files to change the settings.



--
Atul