1. Operating System settings - sergiocontrino/docs GitHub Wiki

OS memory setting

ipcs -lm gives information about the server memory settings

e.g.

max number of segments = 4096                  //SHMMNI
max seg size (kbytes) = 32768                  //SHMMAX
max total shared memory (kbytes) = 8388608     //SHMALL
min seg size (bytes) = 1

also sudo sysctl -a | grep -E "shmall|shmmax" can be used

kernel.shmmax = 33554432
kernel.shmall = 2097152

The suggested setting (pp 101) depends on 2 system settings, PAGE_SIZE and _PHYS_PAGES which can be obtained with getconf (e.g. getconf PAGE_SIZE)

shmall = phys_pages / 2
shmmax = shmall * pagesize

The 2 values need to be added to /etc/sysctl.conf, and the change to be made effective issuing the command sudo sysctl -p

In our case

kernel.shmmax = 271051274240
kernel.shmall = 66174628

The new result of ipcs is

------ Shared Memory Limits --------
max number of segments = 4096
max seg size (kbytes) = 264698510
max total shared memory (kbytes) = 264698512
min seg size (bytes) = 1

Note: the unit for kernel.shmall is pages, not bytes.

CPU clock

TBC

cpufreq-info gives info about the clock setting for the various CPUs.

you can try to set them running at max clock

sudo cpufreq-set -c 0 -g performance

or better (all cpus)

sudo cpufreq-set -r -g performance

check [here] (http://askubuntu.com/questions/318780/how-to-set-cpufreq-governor-to-performance)