Getting nvidia to come up without a connected monitor

I was working on trying to make my Mythbox shut down when idle, and the first big(!) hurdle was getting X to come up properly, when the HDTV is off (and by off I mean off-off, not idle-off), with the nvidia driver.  This was killing me; it kept rejecting the modes I gave it because it had no idea what was connected.

Finally I stumbled upon the fact that you can use their nvidia-settings tool to extract the edid data into a binary file, and then tell the X driver to use it in the Device section:

# So we don't need the monitor on to get panel info:
Option "CustomEDID" "DFP-0:/path/to/edid.bin"
# And tell the driver what is (or will be) connected
Option "ConnectedMonitor" "DFP-0"

Mythbox Power Consumption V2 – 51W

Dropped one tuner card from the mythbox, put the root on an SSD, and set the media drive to spin down… Kill A Watt [amzn] now says it’s 51W when idle.

This still isn’t great;  I’d never leave a 60W bulb burning 24/7 … so next stop is looking into making it shut down when idle, and wake up in time for the next recording.  MythTV has this functionality built in, but not if the frontend is running; I guess I need to homebrew something for that.

The SSD helps it boot in 18s so turning it back on on demand isn’t so painful…

MythTV Power Consumption

… In which Eric discovers a simple way to reduce the power draw of his DVR …

When I built my new MythTV box, I did it with an eye towards power efficiency – both to save me a little money, and to maybe save the planet (hey, it’s just one thing, but it’s the little choices we all make).  So with that in mind, I got a 45W AMD 5050e processor, and Antec 80Plus EarthWatts 380W power supply, etc.  I don’t yet have any “green” drives in it; I’d hoped I could get the root drive to spin down to idle, but so far that’s been elusive.

Anyway, when all was said and done, I had a quiet box that idled at about 65W according to the Kill-A-Watt.  Not awesome, but a heck of a lot better than the old P4 heat plant that it replaced.

But one thing I noticed – when the menu was on the recorded shows listing, and the little preview was playing, power jumped up to around 80W!  And unfortunately, nobody ever exits from that screen, and it’s the one that MythTV returns to when it’s not playing.  So the box sat there for hours and hours decoding mpeg, bringing the cpu out of its low power states, and adding almost 25% to the power draw.  :(

It’d be nice if MythTV would just time this out, and go back to the main menu, or at least stop the preview playback – but you can just disable it in the frontend setup menus, for now.  Go ahead and do it – I bet you won’t miss it, and you’ll save a dollar and a pound of CO2 as well.

Oh, and an addendum: If you have the MePo theme (or other animated theme) running, even that adds to the power bill.  I modified the theme to drop the animations, and chopped another couple watts off the draw.

On edit… the MythTV Wiki has a page on power savings that I’ve updated too.

Coming clean on O_PONIES

The O_PONIES thing came up in the context of how ext3 behaves, how app writers wish that every filesystem behaved like ext3 (in the good ways , of course, not in the bad ways, oh no!) and how generally they’d like a pony with that, too, please. In other words, open your files with O_PONIES and the world is your oyster; the filesystem will grant your every wish.

It’s become the running joke among the filesystem developers I know, but as it turns out I was the one who coined it (I think?) Jeff thinks so too, which is what reminded me. Ted T’so thought it was Jeff, but he was 2 weeks behind the curve. Who knew I’d leave such a lasting impression.

$ grep O_PONIES OFTC-#linuxfs.txt | head -n 1
<sandeen> Mar 15 23:34:10 open(my_configfile, O_PONIES);

I made a tshirt, too:



But it was Val, with her impeccable sense of style, timing, and politics, who had the good sense to make a t-shirt with an extra inkjet t-shirt transfer I gave her, and wear it on photo day at LSF:

LSF Group Photo

LSF Group Photo

I wore mine on day 1, and other than a photo Matt Mackall took, there is no record.

But now you know the secret of the man behind the O_PONIES curtain!

fsync, sigh

As probably everyone who keeps up with linux has heard, ext4 eats data, puppies and babies.  Except, of course, that’s not really true.

The original slashdot headline was quite breathless, I’m sure, but in the end it ended up with a rather milquetoast “Apps That Rely On Ext3’s Commit Interval May Lose Data In Ext4” after someone rose to ext4’s defense.  …erm, or sent slashdot to a reeducation camp.

Well, welcome to Posix buffered IO.

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Defuse your googlebombs!

Ages ago, I “helped” googlebomb gwb’s bio via so that a “Miserable Failure” link pointed there, encouraging google to rank ol’ 43 as the top Miserable Failure of all time.  We were kids, it was fun (I guess).  But now that the Obama web team has permanently redirected gwb’s bio to obamas, we’ve got a time-delay googlebomb misfire.  All those Miserable Failure links are now pointing at Obama – the poor guy has barely had a chance.

If you were one of those crazy kids who put this link up, you might reconsider, assuming, of course, that you have higher hopes for the new US president.

See also here.

A Hardware USB modem for Linux

UPDATE: Seems newer versions of this modem may no longer work. Other sites indicate this may be a country code setting or other issue. See end of post, and comments below.

For a long time, I wanted  to be able to run NCID to send caller ID information to my squeezebox, to my MythTV box, to my laptop via growl and NCIDStatusBar, etc – but the hangup was a decent modem.  PCI WinModems are largely useless; I have no desire to run binary blobs even if I happen to find one somewhere that works.  External serial modems are a possibility but it’s another AC adapter brick, more cables, and heck my server doesn’t even have a serial port.

So I was very pleased to find that Conexant has a new usb chipset (CX93010 + CX20548) which implements the USB CDC (Communication Device Class) standard.

I bought the Rosewill RNX-56USB modem from, and with a minor patch, it’s all working beautifully. I find it a bit funny that in the age of fiber to the home, there’s finally a usable hardware modem again.

UPDATE: Steve, in comments below, points out:

Rosewill support confirms that recent shipments of the modem do not report CID due to an unknown change at the manufacturing level. They say it is out of their hands as the modem is not actually made by them.”

Well, that is a bummer indeed, although information seems sketchy at this point.  Try making sure you’ve set the proper country code with AT+GCI=<proper code>, for starters.