Date: 01 Nov 2001 15:09:47 +0100 From: Dag-Erling Smorgrav <des@ofug.org> To: doc@freebsd.org Cc: Paul Robinson <paul@akita.co.uk> Subject: FAQ addition Message-ID: <xzpr8rimvkk.fsf@flood.ping.uio.no>
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DES
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Dag-Erling Smorgrav - des@ofug.org
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Index: doc/en_US.ISO8859-1/books/faq/book.sgml
===================================================================
RCS file: /home/ncvs/doc/en_US.ISO8859-1/books/faq/book.sgml,v
retrieving revision 1.279
diff -u -r1.279 book.sgml
--- doc/en_US.ISO8859-1/books/faq/book.sgml 2001/10/31 23:26:02 1.279
+++ doc/en_US.ISO8859-1/books/faq/book.sgml 2001/11/01 14:08:37
@@ -11563,6 +11563,62 @@
Please do not reproduce without attribution.</emphasis></para>
</answer>
</qandaentry>
+
+ <qandaentry>
+ <question id="dev-null">
+ <para>Where does data written to <filename>/dev/null</filename>
+ go?</para>
+ </question>
+ <answer>
+ <para>It goes into a special data sink in the CPU where it
+ is converted to heat which is vented through the heatsink
+ / fan assembly. This is why CPU cooling is increasingly
+ important; as people get used to faster processors, they
+ become careless with their data and more and more of it
+ ends up in <filename>/dev/null</filename>, overheating
+ their CPUs. If you delete <filename>/dev/null</filename>
+ (which effectively disables the CPU data sink) your CPU
+ may run cooler but your system will quickly become
+ constipated with all that excess data and start to behave
+ erratically. If you have a fast network connection you
+ can cool down your CPU by reading data out of /dev/random
+ and sending it off somewhere; however you run the risk of
+ overheating your network connection and / or angering your
+ ISP, as most of the data will end up getting converted to
+ heat by their equipment, but they generally have good
+ cooling, so if you don't overdo it you should be
+ OK.</para>
+
+ <para><emphasis>Paul Robinson adds:</emphasis</para>
+
+ <para>There are other methods. As every good sysadmin knows,
+ it is part of standard practise to send data to the screen
+ of interesting variety to keep all the pixies that make up
+ your picture happy. Screen pixies (commonly mis-typed or
+ re-named as 'pixels') are categorised by the type of hat
+ they wear (red, green or blue) and will hide or appear
+ (thereby showing the colour of their hat) whenever they
+ receive a little piece of food. Video cards turn data into
+ pixie-food, and then send them to the pixies - the more
+ expensive the card, the better the food, so the better
+ behaved the pixies are. They also need constant simulation
+ - this is why screen savers exist.</para>
+
+ <para>To take your suggestions further, you could just throw
+ the random data to console, thereby letting the pixies
+ consume it. This causes no heat to be produced at all,
+ keeps the pixies happy and gets rid of your data quite
+ quickly, even if it does make things look a bit messy on
+ your screen.</para>
+
+ <para>Incidentally, as an ex-admin of a large ISP who
+ experienced many problems attempting to maintain a stable
+ temperature in a server room, I would strongly discourage
+ people sending the data they don't want out to the
+ network. The fairies who do the packet switching and
+ routing get annoyed by it as well.</para>
+ </answer>
+ </qandaentry>
</qandaset>
</chapter>
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