anty.info

Comments and help on web development.
4  08 2011

Bitcoin miner died

After three days of debugging and endless frustration I’m sure that my mainboard died. I’ll get a 1:1 replacement, but I’m losing about 8 BTC until I get it.

In the debugging process I put one card on top of another, but didn’t unplug the power cables. Turns out graphics cards turn on the fans to 100% when you switch the power on. And the tiny screws on the back of the one card cut itself a piece of the others fan:

On a related note: I found out that AMDOverdriveCtrl crashes with a segfault when I start it automatically, that’s why I have to set the fan-speeds manually. When I do sudo AMDOverdriveCtrl it works. I don’t know why it doesn’t work in my script, though. It should have root rights.


Bitcoin

2 Responses to “Bitcoin miner died”

  1. greylion, Said:
    on October 13th, 2011 at 3:51 pm


    The fan had 9 blades total.
    If you break off two more, so every third blade is gone, the fan will be in balance again.
    I’ve done it before with a smaller 9-bladed fan, works fine (and quiet).

    Btw, all scripts are now unable to set root rights in linux, it was too much of a security issue.
    You have to set root rights and execute the command from a C-program (or other compileable program language). Compile it, then call/execute that program from the script.
    I ran into that issue when doing some PHP code, that needed root rights to execute some commands (replicating new zones from a primary DNS server to a secondary/slave DNS server), and discovered setting root rights for scripts had been disabled in the linux kernel, and will probably never be enabled again.

  2. anty, Said:
    on October 14th, 2011 at 4:48 am


    Good idea with breaking the other blades. Right now it runs pretty quiet with 40% and one blade missing. I’ll probably break the other blades when this changes.

    I think I solved the root problem:
    A script in /etc/init/ starts another script in /usr/local/bin/ with the following statements:

    description "Start BTC Mining"
    start on runlevel [2345]
    stop on runlevel [!2345]
    kill timeout 30
    script
    LOGINUSER=root
    #Wait 30 seconds to make sure X is started.
    sleep 30
    exec /usr/bin/screen -h 0 -dmS gpu0 su -c '/usr/local/bin/startminer.sh 1 13' ${LOGINUSER}
    end script

    If I set “LOGINUSER” to “root” AMDOverdriveCtrl (which is started in startminer.sh) doesn’t crash with a segfault anymore.
    But it exits after it set the profile for the specified interface. So no further fan-control and I can’t explain why.

    Thanks for your very helpful comment, greylion!

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