Running a small server...memory troubles...

[Duane Attaway]

On Thu, 26 Jun 2003, Matt G wrote:

> So...I got that little machine revived (I used a defibrillator to get it
> started.)  Actually, it's running just fine now.  The rough specs are:
> 
> AMD K6 233mhz
> 256mb ram
> 4gb hdd
> RH9 run level 3
> Running several services...sshd, httpd, etc.  

That's several times as much memory than mine!  I'm using 32MB with only 
166MHz and that's plenty fast for me.

> So, I'm watching 'top' to watch my system performance.  The past few
> days, it's been getting slower and slower.  At start up, with ssh
> connection, I see about 64mb ram used.  It starts creaping up...and
> up...  then I start a sftp transfer (of 180mb) and it shoots up...now
> there are 252mb ram used...only a few free.  Is that normal?  So...I
> waited for the file to finish transfering...and the memory went up to
> 247mb used...and stayed there.  Does running a server that's not doing
> anything except a few connections take 250mb?  Or perhaps I'm doing
> something wrong.

Much of the memory will be mapped and cached as time goes on.  This is 
normal and good.  Libraries and filesystem information will be cached and 
bumped if things start approacing swap area.  Unless one of your 
applications are bloated and has a memory leak.  That's when things get 
messy fast.

> Also, in 'top' I see lots of stuff running, and I'm not sure it should
> be.  like...I see 8 httpd processes...each using 3% of the memory.  5
> for mingetty, several for kscand/*.  Am I doing something wrong?

Hit the capital "M" key in top to sort things in terms of memory usage.  
Top also gives you a "k" command to kill a process that you determine to
be an offender.  You can also sort by user with the "u" command.  Need to
display just the active processes?  The "i" command will filter the
display to what's important.  Other exotic top options such as color
mapping are described in the man page.

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