[kde-solaris] swap space requirements [was: KDE 3.1.4 - Can't talk to klauncher]

Richard kdesolaris at nergenshuizen.nl
Mon Jan 26 23:40:39 CET 2004

> Yes, you do need to increase swap whenver you increase core RAM.
But that's a bit bizarre isn't it? If (according to a Sun engineer) 
"available memory" is roughly RAM + swap, the fact that adding RAM 
means you have to add swap just doesn't make sense from a logical 
point of view.

> Especially for workstations which come with a small amount of core
> RAM to begin with. Whether it should be done at 128MB or 256MB,
> that's a matter of tolerance. But, 128MB RAM is significant enough
> to warrant increasing swap, especially when you had very little
> swap to begin with.
Until december 31st I ran Solaris8 on a doubleheaded Ultra5 with 128M 
swap and 192M RAM (no KDE) and I had problems once, when I had too 
many OpenOffice documents opened. I changed the Ultra5 for a 
Blade1500 with 1G RAM and 1G swap and I do run into problems, and I 
haven't even started running OpenOffice on it. (Not quite a fair 
comparison, see (*) below.) 

> Actually, database servers or geologic analysis systems usually run
> on enterprise-class multiprocessor servers, not on desktops. The
I used to admin geologic analysis systems as well as databaseservers 
that never needed more swap than RAM. In fact, we only increased swap 
from half the amount of RAM to 1.1xRAM because we needed coredumps 
when a machine started crashing randomly (this was solaris 2.6, the 
problem was traced back to a faulty terminator on an external 
Right now, I admin databaseservers that do have a lot more swap than 
RAM, and they seem to run just as nice. 
So, in my opinion, there is no rule of thumb, other than add swap or 
RAM if you find your machine is lacking. In which case you scaled 
wrong, or loaded it with more than originally intended.

> > I really doubt that KDE should require 4 times the size of the
> > physical memory to run. If so!? It must be really, really badly
> > broken (hopefully not by design).
> I never said KDE required 4 times core RAM. What i said was:
> the rule of thumb for sizing swap is at least 3 times core RAM.
You did say that it's not surprising running out of swap with 640M RAM 
and 1G swap. Depending on what you do, it can be very surprising. 
_IF_ my klauncher problems are caused by lack of RAM or swap, I would 
be very surprised, and annoyed as well. Because I do the same job 
with the Blade as with the above mentioned Ultra(*), and on the Ultra 
I probably had more xterms open, because I didn't have to restart my 
GUI every few days. 


(*)The Ultra5 ran Openwindows, Netscape Mail and Mozilla. The 
Blade1500 runs KDE, KMail and Konqueror.

Het begint met margarine, en het eindigt met de teloorgang van
alle menselijke waarden!
  -- de Volkskeuken, 28 oktober 2003

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