abnormal consumption of RAM

Hello
sorry my english
I custom opensuse using the tool as an appliance susestudio.
I choosing the basic template opensuse 11.2 “Server A text-only basis”
installation and I encountered a problem in RAM. I encountered an abnormal consumption of RAM up until all.
I have tried with the kernel 2.6.31.5-0.1.1 and with 2.6.31.12-0.2.1.
can you give me a suggestion on how to do solve this problem?

On Tue, 18 May 2010 17:46:02 +0000, antoniospatera wrote:

> I encountered an
> abnormal consumption of RAM up until all.

How are you determining this?

Jim


Jim Henderson
openSUSE Forums Administrator

1 day after boot I found that the RAM was full and the system began to swap. Using the command “top” I trussed no process that occupies the entire ram

antoniospatera wrote:
> 1 day after boot I found that the RAM was full and the system began to
> swap. Using the command “top” I trussed no process that occupies the
> entire ram
>
>

perhaps you are more familiar with the way Redmond software uses
RAM…that is it continuously empties RAM when it is not being
used…Linux has a better idea: Unused/free RAM is totally wasted!

that is, if nothing needs the RAM then 1) why go to the trouble of
releasing it and 2) maybe what is in the RAM now will be needed again
in one second, or one hour…or one day…

so, why release it when you might just have to go fetch exactly the
same thing from disk AGAIN in one second…or one day…

therefore Linux RAM looks full to those who don’t understand what top
is telling them…look again at top it has SEVERAL memory counters
telling you the entire story (once you understand how to read it)…

that is, the memory “used” is not the actual memory “in use” by
applications…it is instead the total of memory “in use” by
applications running now PLUS all memory which “WAS in use” but is no
longer but may be again in one second (one day, etc)…

click some stuff to life while watching top bounce…the “%MEM” column
in the lower chart will go up and down and the “Mem:” line in the
upper part will also jump…but, keep your eye on the memory “free”
you have not “run out of memory” until the system can not RELEASE the
“WAS in use” RAM fast enough to fill the new needs…

make sense?

there are several discussions on this in these fora and on the
internet in general…as well as all the details you need on how to
correctly understand top…

oh, and -=welcome=- to the better way to use memory:
Unused/free RAM is totally wasted!


DenverD (Linux Counter 282315)
CAVEAT: http://is.gd/bpoMD
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CMedia 9761 AC’97 Audio

Hi DenverD,

Thanks you for your answare. But I still have a doubt: Is it possible that after installing my custom opensuse, it starts with 80 MB of memory used and then after 24 hours the memory used is 512MB? The problem is that I did not run anything, the only processes running are the process started by default by the OS. Moreover, using top command the %MEM remains constat for each process, and the process with a greater memory consumtion has 0.2 % used.
I expect that used memory remains constant or has a minor increment considering that there are not other processes running, just the basic process used by the OS to start and the TOP command used for monitoring the memory.
Thanks again,
Antonio

On Wed, 19 May 2010 08:46:02 +0000, antoniospatera wrote:

> 1 day after boot I found that the RAM was full and the system began to
> swap. Using the command “top” I trussed no process that occupies the
> entire ram

When in top, try sorting by swap usage (F and then p) - that should help
identify what’s using the swap space.

Jim


Jim Henderson
openSUSE Forums Administrator

antoniospatera wrote:
> Is it possible
> that after installing my custom opensuse, it starts with 80 MB of memory
> used and then after 24 hours the memory used is 512MB?

yes…
after 7 hours my “used” (of 1 GB) is 1018996 with 16728 “free”

> The problem is
> that I did not run anything, the only processes running are the process
> started by default by the OS.

in 24 hours you will have run several cron jobs and a few dozen
‘services’…well, just top along could cause lots of stuff to be
lying around in RAM, and in the “used” category…

remember, since “used” does not equal “in use” it is possible that
every flicker of top’s changing is still in memory…waiting to be
pushed out when you do start up other processes

now, there is a question you have not asked: Is it possible that my
custom openSUSE is broken and is eating memory?

yes that is possible, but so far you have not yet shown me anything
that makes me think that is the case…

tell me:

  1. how much experience/understanding of the way Linux handles RAM do
    you have?

  2. how much RAM is installed

3: is this a version of openSUSE running on hardware or in a VM? what
system is the VM’s host?

if you suspect a “memory leak” or “abnormal consumption of RAM” just
go ahead and do everything you can to cause your system to actually
start swapping…watch top as you crank up all kinds of stuff and see
how long it take you to eat up all of the “Swap - free” i predict it
will take longer than you think because the system will get busy
dumping out all the stuff in RAM that it doesn’t need…

keep up with tops numbers as you do that, and maybe you will then
understand what i’m talking about…and, do some random reading from
a search like this: http://tinyurl.com/32bbsmr

and, i guess you can probably find the same info in your own lingo
(Italian?) [by the way your english is GREAT!] hey, you might find a
person next door with lots of Linux experience, try looking for a
local Linux User Group here: http://www.linux.org/groups/


DenverD (Linux Counter 282315)
CAVEAT: http://is.gd/bpoMD
posted via NNTP w/TBird 2.0.0.23 | KDE 3.5.7 | openSUSE 10.3
2.6.22.19-0.4-default SMP i686
AMD Athlon 1 GB RAM | GeForce FX 5500 | ASRock K8Upgrade-760GX |
CMedia 9761 AC’97 Audio