'ps' behavoir in Linux - Was - Re: array limits

[Jerry Rains]

On Sunday 18 April 2004 11:21, Fairlight wrote:
> Y'all catch dis heeyah?  Jerry Rains been jivin' 'bout like:
> > Ok, the main problem I seem to have is with the desktop Linux I am using.
> > This morning I rebooted the system to shut down any extra processes and
> > logged into tty1 and tty2 to start a dclerk process then see what was
> > going on.  I did a 'free' command and there was no swap memory being
> > used, however with only the two text logins dclerk was still swapped out
> > on my system.  The logon header confirmed that my system is indeed SuSE
> > 8.2.  Since I only use this system for my Desktop needs, I'm not going to
> > worry about why.
> >
> > My problem is at work so I dialed back in this morning.  The system was
> > idle and ps aux worked fine.
> >
> > SuSE Linux on iSeries -- the spicy solution!
> > Have a lot of fun...
> > filepro at as400linux1:/var/appl/filepro> w
> >   9:13am  up  3:22,  3 users,  load average: 0.07, 0.03, 0.05
> >   USER     TTY      FROM              LOGIN@   IDLE   JCPU   PCPU  WHAT
> >   root     pts/2    -                 8:50am 23:33   0.00s   ?     -
> >   filepro  pts/3    -                 9:13am  0.00s  0.64s  0.02s  w
> >   filepro at as400linux1:/var/appl/filepro> free
> >                           total       used       free     shared   
> > buffers cached
> > Mem:       1001668     261940     739728          0      51004     127036
> >                -/+ buffers/cache:      83900     917768
> >                Swap:       996020          0     996020
> >                filepro at as400linux1:/var/appl/filepro> ps aux | grep
> > dclerk filepro  14020  7.0  0.1  2480 1204 pts/0    S    09:14   0:01
> > /appl/fp/dclerk vregstr -s1 -h Vregister -d
> >                filepro  14038  0.0  0.0  1740  656 pts/3    S    09:14  
> > 0:00 grep dclerk
> >                filepro at as400linux1:/var/appl/filepro>
> >
> > So the answer is, even though we have 1Gb of memory, we don't have enough
> > memory to prevent swapping during operations.  I'll look into seeing if I
> > can move some of the memory from the OS400 side to the Linux partition.
> >
> > Thanks to all who helped.
>
> But that doesn't make a heck of a lot of sense, unless you've confused the
> issue.  You're saying on SuSE 8.2, you can have zero swap used, and dclerk
> is still swapped out.  That's what you said.  At least, that's what I read.
>
> Then you said that the system at -work- has a gig of memory, and you point
> to ps auxww working fine there, and showing arguments, etc.

Actually, I used 'ps aux'  I didn't have to use 'ps auxw' or 'ps auxww'

>  IOW, the process is not swapped out--on a totally different system.
>
> The question is, why did you show stats from the iSeries that -isn't-
> having problems instead of stats from the system that -is- having problems?

Because I first noticed the problem on the iseries.  I was only using my home 
system because it was convenient and it seemed to have the same problem.

>
> FWIW, I'm seriously questioning why 8.2 would be swapping out dclerk.  What
> kernel revision comes up in `uname -a` on the 8.2 system, out of curiosity?

I included that in one or two of the emails, but here it is again.

jmrains at Coastal:~> uname -a
Linux Coastal 2.4.20-4GB #1 Mon Mar 17 17:54:44 UTC 2003 i686 unknown unknown 
GNU/Linux
jmrains at Coastal:~>

> If it's old enough, it could be a mutant <2.4.15 system, and then this
> would start making a hell of a lot more sense, given the VM model issues
> extant through that period.  Indeed, I heard many reports of processes
> being swapped out in favour of disk cache (a la Windows) in the earlier
> days of the 2.4 tree's new VM, notably from 2.4.3 through 2.4.16.  "Have
> you done an update of the kernel on that system to the latest revision?"
> would be my next question.

I used Synaptic to update the system after I installed it about 6 weeks ago.  
I don't think that updated the kernel.  I'll do another update and see if 
that helps.

>
> Show the `free` output from -that- system.

jmrains at Coastal:~> free
             total       used       free     shared    buffers     cached
Mem:        254820     250896       3924          0       5652      45952
-/+ buffers/cache:     199292      55528
Swap:       257032      50556     206476
jmrains at Coastal:~>

>
> You have a gig of memory available on the iSeries, that's apparently -not-
> having issues, and you want to toss more at it,

The info you saw from the iseries was taken yesterday morning while the 
business was closed and the system was idling.  I mentioned that in my email.  
I noticed the problem while we were operating with about 35 users.

Jerry

> even though you're saying
> the problem is your desktop 8.2 system.  This makes less sense to me by the
> minute.  Could you please clarify the situation, and/or give the relevant
> output from the problem platform rather than the good one?
>
> Something isn't adding up--either through misinterpretation on my part, or
> because something's gotten confused somewhere.  Let's make sure we address
> the right problem.
>
> mark->