I use "tuned" myself, with the "virtual-host" profile. RedHad page
Power_Management_Guide/tuned-adm
I might have tweaked it a little, can't remember, but I think "tuned" is responsible for my vm.swappiness = 10. I don't really think about it, it just works, otherwise I just choose another profile which fits.
Paste:
Tuned is a daemon that monitors the use of system components and dynamically tunes system settings based on that monitoring information. Dynamic tuning accounts for the way that various system components are used differently throughout the uptime for any given system. For example, the hard drive is used heavily during startup and login, but is barely used later when a user might mainly work with applications like OpenOffice or email clients. Similarly, the CPU and network devices are used differently at different times. Tuned monitors the activity of these components and reacts to changes in their use.
As a practical example, consider a typical office workstation. Most of the time, the Ethernet network interface will be very inactive. Only a few emails will go in and out every once in a while or some web pages might be loaded. For those kinds of loads, the network interface doesn't have to run at full speed all the time, as it does by default. Tuned has a monitoring and tuning plugin for network devices that can detect that low activity and then automatically lower the speed of that interface, typically resulting in lower power usage. If activity on the interface increases drastically for a longer period of time, for example because a DVD image is being downloaded or an email with a large attachment is opened, tuned detects this and sets the interface speed to maximum to offer the best performance while the activity level is so high. This principle is used for the other plugins for CPU and hard disks as well.
And....
virtual-guest profile:
This profile is optimized for virtual machines. It is based on the enterprise-storage profile, but also decreases the swappiness of virtual memory. This profile is available in Red Hat Enterprise Linux 6.3 and later.
Here is the value of my current profile:
[admin@server]# tuned-adm list
Available profiles:
- laptop-battery-powersave
- spindown-disk
- virtual-guest
- server-powersave
- default
- desktop-powersave
- virtual-host
- throughput-performance
- latency-performance
- enterprise-storage
- laptop-ac-powersave
- sap
Current active profile: virtual-host
[admin@server]#
It works... and might show you some info on what to choose in your swappines
- and thank you for asking, was actually thinking of changing profile to "virtual-guest" instead, but need to read more because I can't remember why I picked that specific profile back then
, think it was because I wanted to reduce swapping and I/O traffic on my KVM VD. But I will read up on it and maybe file a
hint.
Or just like Alex said:
"edit /etc/sysctl.conf
add:
vm.swappiness = <value>
replace <value> with a number 1 to 100
Many people say just to add an "echo <value> > /proc/sys/vm/swappiness" - but this wont persist after a reboot. Sysctl is a utility provided by most distributions to set this up after reboot."
vm.swappiness = 10 is just like no swap at all, but still some
). 