[lug] sluggish machine

Nate Duehr nate at natetech.com
Tue May 19 16:18:44 MDT 2009

I'd look first at two things... 

1. RAM usage (is it swapping like mad?)
2. I'd wonder about a failing hard drive (anything in /var/log/messages
that looks suspicious?)

Next I'd grab a CD with memtest86 on it (CentOS install CD, for example
has it... you just type memtest86 at the CD boot prompt) and let it go
to town for a while on the RAM for a bit just to make sure some of it
hasn't gone south... 

I ran into a machine last night (friend's machine, he asked me to load
some stuff on it) that would just act like interrupts had gone mad after
about 20 minutes of uptime... first the mouse would start to jerk, then
get slow, then the whole machine would lock solid, not even pings.

He had originally thought he had a bad CPU in a "sister" machine he's
already using and replaced the Celeron that the motherboard manufacturer
said was compatible that he'd put in both of these cute little 1/2 depth
1RU sized rackmount machines, with a Dual-Core.  When he heard I'd been
up half the night messing with machine #2... he just ordered another new
Dual-Core and called the retailer that said the motherboard and CPU
combo of the Celery and the motherboard "would work" and told 'em they
were getting their Celeron processor back.  

We'll see how he fares.  I tried every damn setting in the BIOS, I
swear, trying to stabilize that thing... sometimes it would last 5
minutes, other times 65 minutes... but eventually it would just lock up
hard on CentOS 5.3... sigh.

Old Sun hardware would have at least told me what was wrong instead of
wasting 4-5 hours of my life.

Lesson learned:  I need to stop loading other people's computers with
OS's and things for them!  LOL!  Oh wait, maybe that wasn't the correct

Nate WY0X

On Tue, 19 May 2009 16:09:56 -0600, "Davide Del Vento"
<davide.del.vento at gmail.com> said:
> Folks,
> I'm having a weird problem. My laptop is slowing down often, up to a
> point where it becomes unusable. Then it return faster as it was, or
> sometimes (like when I wrote the first draft of this email) still very
> slow, but usable - I am typing about two words forward the ones it is
> showing on the screen.
> *********************
> The facts:
> The machine becomes incredibly slow, system monitor reports 100% CPU
> usage, and many windows (most notably firefox) become irresponsive and
> grayed-out.
> *********************
> The clues:
> System monitor (as well as top) does not report a single process that
> is hogging all the resources, but it might not able to refresh often
> enough. The top-six for memory and CPU are firefox, xorg, evolution,
> thunderbird, system monitor itself and (oddly?) geyes. The rest are in
> the single digit (or even 0.something) range.
> The obvious suspects are javascript in the large number of pages I
> keep active in firefox (I need them, don't suggest to not use them,
> they are almost all work related, besides gmail for chatting with
> family and friends - maybe chrome would have been better to pinpoint
> the guilty site, but we don't have it for linux)
> On a similar system (older hw, same OS, maybe slightly different
> packets installed - oddly less carefully picked, like skype) they the
> same websites don't create this mess! So it's not (entirely) web's
> fault.
> I did deleted my .mozilla directory and let firefox re-create it
> again. Painful (autocompletion, history, settings lost, etc) and
> useless: the problem si exactly the same. I unistalled  firebug (but
> it was disabled...), I uninstalled completely firefox-3.0 and all
> related packages (gnome-support, ubufox, etc), did apt-get autoclean
> and autoremove. After reinstalling (firebug excluded) the problem is
> still here (less frequent, maybe...)
> RootKit might be a possibility, but nmap didn't find anything, and
> rkhunter, unhide and chkrootkit didn't find anything "too strange"
> (well, it did find something, but many people online say that are
> false positive - or are they the RootKit authors? - and then a true
> positive might hide in the list). And I trust more nmap than
> rkhunter, unhide and chkrootkit.
> Fragmentation may contribute to the issue, since everything started
> when I had to create a couple of multi-gigabyte files (suddenly
> raising my / usage from ~30% to ~70%) and I had to read these files
> with my own python scripts to do some data-analysis. During that time
> the system was REALLY sluggish and started to swap, but at the end the
> process was successful. But fragmentation does not explain the 100%
> CPU usage (which files should I check with filefrag -v?)
> *********************
> The system:
> Ubuntu Hardy 8.04.2 - fully kept updated
> Linux-2.6.24-24-generic  i686
> Gnome 2.22.3
> Dell Dual Core U7600 @ 1.2GHz
> 2GiB RAM
> Usually used with Dell dock-station and external keyboard, mouse and
> monitor.
> *********************
> Do you have any suggestion? Even if not, thanks for reading this long
> message.
> Bye,
> ;Dav
> _______________________________________________
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  Nate Duehr
  nate at natetech.com

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