On Sat, 28 Sep 2013 13:11:36 +0200 Leszek Lesner <leszek.les...@web.de> wrote:
(...) > > disk? Here is a configuration file: > > http://meets.free.fr/Downloads/BentoVillageProject/Configurations/System/etc/sysctl.d/50-local.conf > This is no real solution it is more of a workaround if you only have > workloads that don't go higher than the actual physical memory on your > computer. But if it goes higher than that all hell breaks loose & the > system becomes unusable as it starts swapping out like crazy. I had to control the kernel swappiness this way in a machine where 192 MB RAM only was available (and no way to upgrade, the machine would not see it when more ram was installed). I had noticed the swap started to be used when an amount of RAM of 30% or a little more was still available. > We tested such scenario in neptune with sysctl tweaks and especially a > config like you suggest. Some such as or the same? It is only lately that I tried 0 as a value and I can only say it is really better so far. > It only works fine as long it does not start > swapping. We messured that it is necessary to have around 250 mb to keep > the desktop (in our case KDE Plasma) and applications alive(keeping the > mouspointer responsive and clicking on apps does not cause a long halt > until the system reacts). I would not dare using any KDE application with so little RAM, unless only Openbox is used as main environment. :) > This might vary for LXDE as it tends to use a > lot less for the desktop but I can't say it for sure as I never tested > this. > > Else, I configure 20% or 25% max in the initramfs.conf file > > (under /etc/initramfs-tools) ie: COMPCACHE_SIZE="20%" > > > > (I have explained in another thread that 50%, which is the default in > > Ubuntu for a > > reason which is unknown to me, might take too much from the CPU... and the > > above > > configuration is what I have been using in several distributions since > > several years > > with success, as well as a few dozens of users whom I provided with remixes > > having > > this setup). > Compcache is deprecated as far as I know so this config should not have > any effect. When has it been deprecated? I thought as long as the files where there it was meant to be used? I'll check and change method if necessary. > To reduce the zram swap space you need edit it in > /etc/init.d/zram-config . Be carefull there as it does not list it up as > percentage or so but it uses a shell script approach to calculate > physical ram available / 2 . Its not that trivial to change that as > shell script calculation does not support floats. So what will happen if I change '/ 2' and use '/ 4' ? > > Let me also add a word about the swap to disk : it is highly desirable to > > avoid > > swapping to disk, because it is very slow compared to swap to ram and > > therefore > > likely to trigger freezes. > A combination of zram and disk swapping with the priority to zram might > be better as only using zram when facing very low ram and very low zram > availability. If you don't forget to forbid the swapping tendency of the kernel. I have kept an eye on the processes in htop many many times when I could see apps starting to slow down and would also open a session in a tty for this purpose if it was all slowing down too much to be even able to follow the evolution of the processes from within a X session. I don't consider the sysctl config part as a workaround so far, but as a must, even in the machines where I am happy to have 3 or 4 GB RAM. Regards, Mélodie -- Mailing list: https://launchpad.net/~lubuntu-qa Post to : lubuntu-qa@lists.launchpad.net Unsubscribe : https://launchpad.net/~lubuntu-qa More help : https://help.launchpad.net/ListHelp
