[CentOS] Flush memory on a server?

[Gordon Messmer]

On 09/09/2017 04:43 AM, Nicolas Kovacs wrote:
> I read up a bit on RAM consumption, and now I wonder if flushing the
> memory cache regularly is a good idea.


Typically, no.  Whatever pages of memory the system has swapped out are 
pages that the kernel's counters indicate are less often used than the 
pages that are in RAM.

The presence of pages in swap isn't necessarily bad.  If, on the other 
hand, you were seeing pages actively swapped in and out of swap, that 
might indicate that the system needs more RAM than it has.

You can tune how conservative the system is about swapping memory in 
exchange for file cache by setting the "vm.swappiness" system parameter.