Re: Pipeline Problems

[Fraser Farrell <fraser@trilobytes.com.au>]

Tom,

First a question of my own. I've finally downloaded the ~1.8 GB of compressed 
TASS data from crocus.physics.mcmaster.ca. From the quick look I've had at 
their contents, it's all text files....which are going to expand greatly when 
unpacked. How much room will I need for the decompressed files?


> Later it occurred to me that the computer may have "lost" some memory.   It
> had been running a long time since a reboot.  The computer that failed was
> my "Wall-Mart" Lindows special.

>From the little I've read about them, Wal-Mart seems to be a huge discount 
variety store of some kind? If so then assume they're aggressively sourcing 
the cheapest possible suppliers and squeezing them. And in the computer world 
this can mean inadequately-tested low quality parts.

Personally I would suspect faulty RAM or some other hardware problem rather 
than Linux. The Ultimate Boot CD (www.ultimatebootcd.com) contains several 
good memory and hardware testers - and unlike the computer factory, you have 
the option of running a hardware test for many -hours-.

Also check that you haven't put a live mobile phone (or other radio 
transmitter) beside your computer or its cables. Can cause all sorts of 
strange errors. I see this problem a lot in offices.

Recently I discovered a customer's intermittent wierd computer problems were 
being caused by his X-ray machine. There was a crack in the shielding, which 
allowed a narrow beam of X-rays to escape and "illuminate" the keyboard in 
the surgery! I was aware of this possibilty because of earlier experience in 
trying to keep lab computers running near kilotons of uranium ore.

You wouldn't happen to have a blob of some exotic isotope from your old 
workplace, sitting on a nearby shelf? Glowing in the dark...? :-)


> It is common for linux computers to lose track of memory?

Mine don't; but thanks to prolonged neighbourhood roadworks & construction 
they often lose supply of electricity. Best uptime so far is a measly five 
months, and that's with a UPS here that can supply for ~2 hours. Maybe I 
haven't been able to run long enough for subtle memory leaks to have any 
effect?

But I've got customers in places wth more reliable electricity who are doing 
much better than me. One of them has recently achieved 4 years of 
uninterrupted service from his Linux mailserver / internet gateway. And this 
is on a recycled computer.

It -is- normal for Linux to fill up whatever memory is available, but this is 
by design, because it's faster to grab frequently-used code & data from 
memory instead of re-reading it from disc.


> Along the same lines, from time to time my linux machines will fail to
> respond in a Konsole window.  There is a prompt but it does not see
> keyboard entry.

Personally I try to avoid the x.0 releases of any Linux because that's 
typically the version with the bugs. Usually because the distributor shovels 
in tons of New And Exciting Stuff that's still a bit wobbly. So I wait for 
the x.1 or x.2 releases before installing them on important computers.

Check under KDE's Look N Feel for your windowing behaviour. In particular, the 
"focus policy", which controls where your active keystrokes and mouseclicks 
are going. Your problem might be that your "focus" is not on the foreground 
Konsole until you mouse-click it - meanwhile your keystrokes are going unseen 
to another application in the background?

Incidentally Windows XP can have the same problem. But most people won't 
experience it because the install default is "foreground window always grabs 
focus".


> Is there a good way to clear out "dead" jobs?

 - KDE System Guard

 - the "kill" or "killall" commands (do a "ps" first to find the job's process 
IDs)

 - restart KDE (after saving your work)

 - restart the computer :-)





cheers,


-- 

Fraser Farrell

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