Why eats my Knoppix so much memory?

[roger_girardin]

i have a similar comp

i have installed by hand (apt-get) on a woody os

i can't give you the link for testing
==> someone has cracked it and changed the root pass

i have no time now to look for the solution

[Photonix]

After donating my server additional 64MB of RAM (I know it´s not much but I only have 2 banks of RAM available, so I replaced a 64MB with a 128MB) I believe there must be something completely wrong with it..

It still eats up to 95% (with opened dselect) of the Memory, at the moment 85%.

What happens If I put 512 or more MB in it? Will it still continue to gorge my mem?



Any suggestions?

[user unknown]

Is the amount of memory used all the time, or only at a peak, while the script is running?
I would start top first, then call the server, and compare the values, and compare it to the usage after a while - few seconds.

[OErjan]

wait a minue here. could we se a dump frpm top please. you see linux never reclaims used memory. it keeps the "cashe" there as long as there is no demand for more ram. linux reasons that memory is faster than the fastest hdd so beter use all available instead of swapping when not needed.

[Dave_Bechtel]

--Whaaaaaat? Of *course* Linux reclaims used memory. That's what the swap space is used for, among other things. Do a google search on "swappiness":

http://kerneltrap.org/node/view/3000

wait a minue here. could we se a dump frpm top please. you see linux never reclaims used memory. it keeps the "cashe" there as long as there is no demand for more ram. linux reasons that memory is faster than the fastest hdd so beter use all available instead of swapping when not needed.

[Dave_Bechtel]

--Here's something I noticed right off the bat:

[[ Before I start to explain my problem I want you to know my system details:
Knoppix 3.4 HDD-Install
AMD K6 500Mhz
192MB Memory
8GB HDD (1GB Linux Swap)
Connected to Internet via DSL over Router
10Mbit LAN
]]

--First of all, an AMD K6 is not the best thing to be running a server on. Personal experience with older AMD's tells me they're flaky, and generally slower than Intels at the same speed rating. If you can get a faster (used, even) machine with an Intel (or AMD Athlon/Duron) of 800MHz or better, that would be a good step. However, I realize that $$$/resources may be limited, so I will try other suggestions as well. (My "fast" machine is currently a 900MHz AMD Duron because they were more affordable at the time, so I know whereof I speak.)

--Try enabling DMA and 32-bit mode using hdparm:
' hdparm -c1 -d1 -u1 /dev/hda '

--This should speed up the hard drive. (If you start getting DMA errors, shutdown immediately and reboot - and do not re-enable the hdparm.)

--Increase the RAM to at least 256MB, if possible. More is better. If using the machine as a server, do not run anything else on it (disable all GUI, and do not use it as a desktop machine.)

--Replace the 10MBit LAN card with 100MBit. Trust me, it makes a difference. However, you also need 100MBit infrastructure (hub/switch, cat5) to really take advantage of it. Personally, I was happy with 10mbit myself until switching to 100. Worth the investment -- 10mbit only does about 700KB/sec, while 100mbit does ~10 times that.

--Recompile your kernel. I can send you a sample config file, if you want. Especially if you're using the default one that came with an older Knoppix, it's worth your while to tweak it for your specific hardware -- you can save disk space (delete old modules after you get things working right) and memory, and compile things for your specific architecture. My Linuxtips page at the bottom of all my posts has more info on kernel recompiling.

--Outside of that, I know there are things to speedup Apache and the rest, but I don't have personal experience with them. (I'm currently only running Squid on a 233MHz Pentium-1 for my Internet needs.) Your best bet is to google around for speedup tips, and maybe find a guru in your area to also help you with config tips.

--BTW, what kind of web pages are you loading?

[OErjan]

it reclaims it when needed, not before.

[Photonix]

I overlooked the second page, thanks for your comments Dave.

I will try the hints you gave me.

Concerning the 10Mbit: I´m connected over a 10Mbit router, the card can 100Mbit.

I´m a web-developer and currently working on a shop-system, so I understand with database and all the stuff there can be a heavy load, but I didn`t expect it to be sooo slow.

I´m already a little bit fed up with that, thinking already to switch back to windows.

On another port on a different machine I run a windows-server with similar hardware-components, and the sites are served like a bat outta hell.

(I´m not biased at all, I just see the facts)

I already tried to uninstall a lot of software, but with no effect.

Maybe, If time permits, I will try another linux distribution, it seems knoppix is not suitable for my needs

[user unknown]

Sorry, Dave, but I have to disagree.

Performance-Tuning without investigation for the bottleneck, is a waste of time and money and hoping for X-mas.

The page is of less than 14 kb.
A 10 Mbit connection should send it in less than 0.1s.

As far as I understood Photonix, only few users will use this server, so investing in a new CPU would be a buisiness-solution - perhaps.

Photonix: Uninstalling software is giving you hd-space. Will not speed up anything, nor free memory.

You didn't answer my question, about the memory-peek. Not interested?

[Photonix]

Hi unknown,

unfortunately there are no indications for memory peaks while accessing the server (I observe top via SSH). Nor are there CPU-peaks. If there WERE peaks, they would be so short they wouldn´t bother...

Paradoxically sometimes the pages loads *** fast, in less than 1 sec. It's mainly when I access pages with more database-querys than html-words But that´s really seldom.

Maybe that´s a clue, maybe it´s purely apache which causes troubles.

Though I don't know...