On Mon, Apr 2, 2012 at 7:57 AM, Pandu Poluan <[email protected]> wrote: > > On Apr 2, 2012 5:00 PM, "Robert David" <[email protected]> > wrote: >> >> Hi, >> >> maybe write your hw configuration first. Eg: CPUs, graphic cards, HDDs >> (size, speed, type) and others. >> >> Also provide lspci output and /proc/cpuinfo. >> >> Then this is a server, maybe with more than one GB nic. If you dont use >> spare nics disable them in bios. Do the same with other unneeded stuff. >> >> If you can access your server and replace cards, remove everything you >> dont need. Do not lower fans or dont play with cpu voltage. If you want >> to run this server 24/7 it can cause serious problems. It will not save >> you much power. Paradoxly this could lead to higher power usage in >> some cases, because of hotter devices. >> >> Remove spare memory cards, if you dont need much memory, etc. >> >> Robert. >> >> V Sun, 01 Apr 2012 17:04:58 +0200 >> Jarry <[email protected]> napsáno: >> >> > Hi, >> > >> > admin of a colo-center keeps complaining my server is going >> > a little over power-limit (which they have set as ~120W per >> > 24h/avg, while my server needs ~130-135W). So I need to find >> > a way to save at least those 15W, or I will be moved to >> > higher tarif (which means higher costs for server-housing). >> > >> > Before going hard(ware) way, I would like to try first >> > all possible software solutions. What I tried up to now is >> > cpufreqd, CONFIG_NO_HZ=y, and spindown. In addition to that >> > I adjusted fan-speeds to a little lower values and turned >> > off some unneeded peripherials (in bios). >> > >> > Is there anything else I could do? Any tips would be greatly >> > welcomed... >> > >> > Jarry >> > >> >> > > I'd rather have *more* RAM than causing unnecessary swaps. > > Try using a smaller swapfile to reduce swap tendencies. You can always push > a larger swapfile into service when needed. > > There's also a kernel knob to set 'swappiness', but I forget what exactly. > Try 'sysctl -a | grep swap'
Swappiness is the knob you want to set if you want to reduce swappiness. I set mine to 0; swap only when absolutely necessary. In /etc/sysctl.conf: vm.swappiness = 0 On the command line: sysctl -w vm.swappiness=0 -- :wq
