[CentOS] Effectiveness of CentOS vm.swappiness

Mon Jun 8 19:18:18 UTC 2015
Kwan Lowe <kwan.lowe at gmail.com>

On Thu, Jun 4, 2015 at 4:18 PM, Markus "Shorty" Uckelmann <shorty at koeln.de>

> I have lots of C6 & C7 machines in use and all of them have the default
> swappiness of 60. The problem now is that a lot of those machines do
> swap although there is no memory pressure. I'm now thinking about
> lowering swappiness to 1. But I'd still like to find out why this
> happens.

 Thanks for this thread. I'm actually looking at the same settings for a
different reason.  Most of our environment is VMWare-based and one major
difference between the Linux and Windows clients is how they use "free"
memory. Linux grabs it for cache ("Free memory is wasted memory.") but
Windows doesn't appear to touch it at all. This means the VMWare hypervisor
can over-commit memory.