How to reduce 'swappiness' for Suse 10.0

luxor · Beginner Joined: Dec 02, 2006 Posts: 17

Hi,
I came across an interesting article these days on optimizing desktop performance ( http://www.linuxjournal.com/article/8308 ) and found it quite interesting, especially with the comments below it. I reduced the colour settings to 16-bit, ran the DMA for the harddrive but could not reduce the swappiness because when I typed:

sudo sysctl -w vm.swappiness=10

I was informed that the command 'sysctl' was not found. I skimmed the man page for the command and it was there. Can you give me a hint?
I will apreciate your opinion about this thing. If you have some other advice as to optimizing the performance of a computer under Suse I will be glad to read it!

thanks Very Happy

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jimmo · Posted: Thu Jan 25, 2007 8:57 pm Post subject:

if you run sysctl as root, does it find it? My guess is that it is not in your user's path.

luxor · Beginner Joined: Dec 02, 2006 Posts: 17

Yeah, Jimmo, great, that was it ! But now I wonder how to execute the last stage:

vm.swappiness=10 to /etc/sysctl.conf

since I do not have a sysctl.conf file in /etc Confused

is it because I am using another distro or I am again missing something???

jimmo · Posted: Fri Feb 02, 2007 11:57 am Post subject:

I'm running SUSE and it was on my system. Maybe it was somewhere else. Try

find / -name sysctl.conf

and see if it is anywhere else. Also look at the sysctl.conf man-page.

luxor · Beginner Joined: Dec 02, 2006 Posts: 17

well, Jimmo, I tried : find / -name sysctl.conf and received the following:

find: WARNING: Hard link count is wrong for /proc: this may be a bug in your fil esystem driver. Automatically turning on find's -noleaf option. Earlier result s may have failed to include directories that should have been searched.

Exclamation

ffreeloader · Master Joined: Aug 10, 2005 Posts: 572

Have you tried "locate sysctl.conf"? It would need to be run as root though to make sure you have access to all files on the system.

luxor · Beginner Joined: Dec 02, 2006 Posts: 17

Hi, ffreeloader, I tried locate sysctl.conf as root and it said that the command was not found, then looked for the man page and it replied there was no manual entry for "locate" ... there is maybe a bug in the file system... Sad

ffreeloader · Master Joined: Aug 10, 2005 Posts: 572

Well, then try this: ls /etc | grep sysctl. If if your file shows up use one of your text editors, as root, and just add the line swappiness=10 to the file and then save it. That will save the settings for you. You'll have to either reboot or echo the settings to /proc/sys/vm/swappiness again for it take effect.

If the /etc/sysctl.conf doesn't show up using the ls command then you most likely have a corrupt install given the other errors that you have encountered when running the find command. If you want to stick with SuSe upgrade to 10.1 or 10.2 by downloading the .iso images for one of them just to make sure that the bug you have isn't just from a corrupted installation disk or a bug in 10. If you don't want to stick with SuSe there are a lot of other distro's out there.

The last thing to try would be to just create the sysctl.conf file where it should be in /etc. It would be a stop-gap kind of fix, but with the other problems you've run across I'd try a fresh install, but from another set of disks.

luxor · Beginner Joined: Dec 02, 2006 Posts: 17

Hi, Freeloader,it is only yesterday that I read your reply (strange because I usually receive an email notifacation for new posts...) and finally found the file. Even learned the Vim basics in order to configure it Smile

I read the arguments about this issue and now I am actually testing the responsiveness of the system for I want to decide for myself which way (either 0 or 100) will show a better performance. I set swappiness to 0 , works fine for now, anyway I'll soon try it with a value of 100...(I have celeronM 1.4 gh, 256ram)

and I would also like to ask you how can I understand what my processor's L2 cache is....I receive cpu parameters in the console but it doesn't say whether it is L1 or L2

Thanks a lot for the support... and any additional comments are welcome Smile

luxor · Beginner Joined: Dec 02, 2006 Posts: 17

Well, by typing DMESG the cpu information I needed was revealed Smile

but now the question is: since I have set swappiness to 0, why when I type TOP it says that some part of the swap (some 20 % or so) is being used?

ffreeloader · Master Joined: Aug 10, 2005 Posts: 572

luxor · Beginner Joined: Dec 02, 2006 Posts: 17

Thank you for the explanation, Freeloader Smile

I have 256 RAM and at the moment of typing TOP I was running Nicotine, Amarok and was browsing a couple of websites which processes I guess shouldn't be much memory consuming though ... but probably SuSE is "hungry" for memory, as you say...
Well, then, I am thinking of trying Kubuntu ( afaik this is the best Debian distro) along with SuSE but first I'll have to find out how to delete the win-partition, which I do not use anyway, in order to free space on the hdd and test the new Debian installation...

Smile

ffreeloader · Master Joined: Aug 10, 2005 Posts: 572