Energy-saving Linux file server

[richb at pioneer.ci.net (Rich Braun)]

The saga of my difficult installation is behind me, so I thought I'd take a
little time to write down specifics of the system that I just built with the
goal of saving on my household energy bills.  Two days ago the NY Times
published an article on a related topic, search for the article "I Vant to
Drink Your Vatts" via news.yahoo.com.  The article dwelled overly much on the
few watts drawn by all those power-brick transformers and instant-on devices
around the house, without making the more important point:  anything that you
leave on 24/7 should be scrutinized closely to see if maybe it should be
yanked out of the wall and replaced with something more efficient.

First is my bottom-line number:  my old file server drew 86 watts and my new
one draws 46 watts.    I spent a total of $159 on new components.  The 40-watt
savings at NSTAR's rate of 17.8 cents/kwh (starting 1/1/06) reduces a $134
annual bill to $72, a return-on-investment of $62 a year so it's like
depositing $134 at 46% APR.

Some notes on the old server:

* Mainboard: ASUS P2B-L, 550MHz P-III, 384Mb
* Four IDE drives: 2x 30GB, 2x 80Gb
* 3ware hardware RAID, set up as two mirrors
* Typical uptime 6 to 18 months at a time
* Linux 2.2.12 kernel

In addition to energy savings, I also wanted to eliminate one of the problems
with the old RAID setup:  the 3ware board was so old that there was no Linux
driver capable of monitoring and giving alerts for degraded arrays.

Notes on the new server:

* Mainboard: EPIA ML6000EA, 667MHz VIA Eden, 256Mb -- paid $129 to eBay store
* Two IDE drives: 160GB, 120GB -- paid $30 after rebate at Best Buy
* Software RAID1
* Linux 2.6.14 kernel

I happened to have a 256M memory chip and a 160GB hard drive lying around the
spare-parts bin.  If you shop around for those components, you'd find them for
about $50 to $75.  (No, I can't quite figure out a way for Negroponte's hyped
crank-powered freeware PC to come in under $100 build cost...but I am frugal
;-)

Note that the EPIA mainboard comes with the processor chip already installed. 
If you were building a desktop version, you'd want the 1.3GHz processor for
not a whole lot more money.  I knew a fileserver (at least if you can get the
hard drives to stay in DMA mode ;-) doesn't need a beefy processor even if
you're serving a small engineering workgroup.  One note about the
processor--the vendor states that the Eden is running at 600MHz, but this
board actually runs it at 666.67MHz.

As those of you have followed my thread can tell, Suse-10 is probably not the
first choice distro for doing this.  But eventually I figured out most of the
quirks and am happy with the results.

I haven't done any benchmarks but after doing a couple of RAID tests
(unplug/re-plug one of the dries), array resync operates at 37 megabytes/sec
across the two IDE buses.  And a full Amanda tape backup (to my other Linux
box across 100-mbit Ethernet) operates an hour faster, dump rate 8700 vs. 7750
KB/sec.

With the server finally installed, I turned my attention to the big power
eater:  desktop monitors.  A couple months ago I had decided to hold out for
another year until LCD flat-panel prices come down further (manufacturers are
dumping $20 billion into new factories).  However there is a way to save money
now, if you still have any CRT monitors in your house:  eBay.  I'm composing
this on a 17" Proview panel (oriented portrait mode as a 2nd monitor) for
which the after-shipping cost was about $115.  This unit uses 23 watts
(measured--don't trust wattage estimates you read online, they are usually way
high or way low, unless they are from a third party who has actually measured
them) while active and essentially zero in screensaver mode.  Even if I sit at
the PC for 15 hours a day, 7 days a week, this monitor will only use $22 a
year at next year's electric rates.  The old blurry, smaller CRT cost 3 or 4
times as much to operate.

So do some house-cleaning, give NSTAR the middle finger, find a good charity
to donate your basically-OK used components to and/or a favorite dorm roof to
drop them off of.

Footnote about buying monitors off eBay:  hardly anyone bundles the power
brick with them.  Some monitors have built-in power (ie can take 110 volts
directly) but even those probably take a special power cord.  And it's
*really* hard to find a place to buy power bricks arond Boston.  So don't
forget to order the power brick the same day you purchase the monitor.  I'm
facing a 5- to 10-day delay getting a nice Dell 2000FP up and running--learn
from my mistake.

-rich