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2-Cent Tips

Checking for DST (USA Linux users)

Rick Moen [rick at linuxmafia.com]
Thu, 22 Feb 2007 11:53:15 -0800

If you're a Linux user in the USA, your Linux distribution either may or may not properly change to Daylight Savings time on March 11, 2007: A 2005 act of Congress extends Daylight time three weeks earlier in the spring and one week later in the fall, starting this year.[1]

To find out if your system needs updating, just do this:

   $ date -d '27 March'
You should see

   Tue Mar 27 00:00:00 PDT 2007
...if in the Pacific time zone, or something else with "D" in the middle, if in one of the other zones. That's the desired output, a week after the time change. By contrast, if the middle letter is "S" for Standard Time, then your system software definitely and urgently needs updating.

[1] http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2007/02/21/MNGASO8BQ11.DTL

"As someone here (I forget who) said, little incidents like this are expected.  
If you have a group 'alt.fan.red-things', it's inevitable someone will show up 
and say 'red things suck'."   "THINGS TO DO: newgroup alt.fan.vacuum-pumps" 
                          -- Richard Boye' and Alistair J.R. Young, in rasfwrj

One way to test system RAM

Mulyadi Santosa [mulyadi.santosa at gmail.com]
Wed, 24 Jan 2007 23:39:52 +0700

[[[ Mulyadi originally sent this in as a followup to a forward from the [conspire] list - Kat ]]]

Dear Sleepless Gang ;)

> And a follow-up, since some readers may not have understood the point of
> that console session transcript.
Just wanna add something to this stress test using kernel compilation. Before you issue make -j <n>, it would be a better a idea to do:
$ make allyesconfig
This way, you'll make sure you are enabling all kernel configurations. If it is a multiple choice configuration item, Makefile will pick the default preferred configuration for you. This will make stress testing longer and consumes even more larger RAM portion (taken as page cache and compiler's stack & heap)

You could also add V=1 to make kernel compilation more verbose:

make V=1 -j <n>
It will make Makefile produces lots of screen's output and surely put another area of stress.

Still not satisfied? Open an xterm session or just logon to another virtual console. Do this:

$ while : ; done tail -f /dev/zero; done
It is another memory eater that will repeatedly make your kernel engages so-called OOM (Out Of Memory) Killer. Short story, it will exhaust your memory even faster. But IMHO, you only need to do this if you have a real plenty of RAM, let's say 4GB or more.

Just sharing my thoughts..... hope it is useful.



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Published in Issue 136 of Linux Gazette, March 2007