From both a performance and security standpoint, which cipher should I use with openvpn?
According to http://openvpn.net/index.php/open-source/documentation/howto.html#security , the default is Blowfish, and the recommendation/example is to use AES-256-CBC, for its larger key size. Is 256-bit AES the best practice?
Renicing a process to a negative nice level increases the process's scheduling priority. High priority processes are run before low-priority processes. They are also allowed to run longer before being pre-empted (they get longer time-slices).
On a web server, running httpd processes with a negative nice value should reduce context switching and therefore improve overall performance.
Has anyone tried doing this? What kind of a difference does it make? Is response time improved? Does the response time standard deviation increase or decrease? Is throughput improved?
Edit:
I'm not looking to reduce the priority of other processes; and I'm not looking to fix an overloaded system. I'm wondering if negative nice levels effect reduced context switches, and if so what the impact of this is on response time and throughput.