Applications using hard disk too often

Frank J. Laszlo laszlof at vonostingroup.com
Mon Mar 6 12:22:08 UTC 2006


Kevin Kinsey wrote:
> Frank J. Laszlo wrote:
>
>> Michael Tuchman wrote:
>>
>>> I am running freeBSD 5.4 stable on a P133 box with 128 Mb ram. 
>>> Although I don't think I'm overloading the system, it seems that
>>> my system is using virtual memory too often.   Admittedly, this
>>> is a subjective question where 'too often' means only 'more often
>>> than I remember with other *nix-like operating environments on
>>> even weaker machines'.
>>>
>
> Without some clue as to what the system is doing, IMHO it's difficult
> for anyone to speculate why you'd be "swapping" so much.  FreeBSD
> uses all the memory it has because the designers know that "free
> memory is wasted memory" ... I don't know where that statement
> originated, but you'll hear it from FreeBSD programmers if you keep
> your ears open.
>
> One possibility is that you have actually configured **too much swap
> space** (Joshua Coombs, http://www.bsdnews.org/03/tuning.pdf).
>
> I'd also have to say that I'd consider this box to be a tad slow for
> a workstation unless your graphical environment was rather lightweight.
> I've tried GNOME2 on an AMD K6-2 475 with 128 MB and it just
> crawled.  It's slightly better with XFCE, but to get much performance
> from a box like that I'd recommend black/fluxbox or something equally
> easy on the resources.  If this isn't a graphical environment, then
> something *is* wrong, I'd think.
>
>>> Can anybody offer advice on memory management, appropriate
>>> places to read in the documentation, or other useful links?
>>
>
> Advice: with 128MB of RAM, don't open 127MB PDF files  </rimshot>
>
> Reading:  Chapter 2 of McCusick's "Design & Implementation":
>
>   
> http://www.freebsd.org/doc/en_US.ISO8859-1/books/design-44bsd/index.html
>
> and tuning(7) are a couple of canonical resources.  Google is always
> your friend, also.  I apologize if that seems like "RTFM, newb"; it's 
> just
> that IANAE and don't play one on the Internet, either.
>
>
>>> I realize that the answer is 'it depends', so what I am asking is 
>>> really
>>> * How can I find out if I change this annoying behavior for the better?
>>
>
> Experiment?  Add RAM; take away RAM; add more swap; take away some
> swap.
>
> Of course, not all of those could be called exactly 'trivial' to the 
> system.
>
>>> * Would upgrading to 6.0 help?
>>
>
> Possibly, but without knowing the cause it's hard to say for sure;
> IOW, no silver bullet there.
>
>
>>> This is an experimental box only.  There is no critical data on it,
>>> so data loss is not an issue when considering options.
>>
>>
>> The 5.x series was a "transition" release, to ease the pain between
>> 4.x and 6.x.
>
>
> Hmm, I wonder.  4.X to 5.X wasn't completely "painless", (at least, you
> had to take some pains to get it right), so I might contest this.  Any
> further discussion or speculation on this would place this posting in
> the political rather than technical realm, which I am loathe to do.  For
> one reason or another, 6.X is out.  6.X is good.  AFAIAC, 5.X was also
> good and 4.X was good too.
>
>> I would recommend going up to 6.0 (or 6.1, But I have not
>> yet tested it) Doing a fresh install would probably be in your best 
>> interest.
>
>
> The transition from 5.4 to 6.X is quite trivial; the only reason a
> "fresh install" might benefit is if the OP has too much swap and
> wants to configure less during slicing.
>
> It's also possible that doing a fresh install of 6.0 would fix the
> problem, but teach us nothing about the situation we'd hoped
> to learn from??
>
>
I suggested a fresh install due to the fact that 6.0 has improved FS 
support. Including multi threading capabilities. And yes, the upgrade 
from 4.x -> 5.x was a PITA, But imagine the pain involved with a 4.x -> 
6.x upgrade. ;)

-Frank



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