[PLUG] Zot's power cycling for Linux

Zot O'Connor zot at whiteknighthackers.com
Mon Apr 26 11:22:02 UTC 2004


On Fri, 2004-04-23 at 19:54, Keith Lofstrom wrote:
> Zot writes:
> > I have a remote machine that is locking up.  I want to be able to shut
> > power down for 5 minutes, and then power back up.  The power supplies
> > have a timeout reset on them, so flicking it on and off will not
> > work....
> 
> Have you considered a watchdog timer board?  These run around $100, IIRC,
> and will do a hard reset of the machine if they are not tickled by code
> every so often.  I was having problems with a machine back in my BSDI
> days, I got a such a card, wrote a BSDI driver based on the supplied Linux
> driver,  and it worked!  When the machine went zombie and stopped tickling
> the watchdog board, it would wait 30 seconds and then do a hard reset.
> 

The problem is that this server is still in Oregon and I am not.  Adding
boards is difficult, but unplugging is easy :)

The syustem is a dell power edge, so I wonder if it has a watchdog built
in.



> 
> Another alternative would be to temporarily attach a second linux box
> with a signal from the parallel port controlling a 5V relay.  You could
> have two machines control each other this way.  Finally, a task slow
> enough to run on a 386-12 machine!  That's 0.012 GHz for all you young
> people.  :-)
> 

Well that is what I was looking for this weekend.  I remember these from
10-15 years ago and they were $30-70 to connect to a modem.  Now I am
seeing them for $160-250

What I am now wondering is the UPS.  I have found I can shut off a UPS
via a serial command.  What I do not know is what happens next.  The
Dell requires that I power off for 5-10 minutes, there's a "protective"
delay on the power supplies.  If I tell a UPS to power down, what
happens?  Does it power down until I tell it to power up?  Does it power
down until line power is back on?  In this case line power is already
on...

I was hoping for a solution in the $30 range.  I could grab a relay,
attached to a parallel port, then to a sock, and put it all in a
junction box and ship it, but that sounds a bit iffy to rely remotely.

> Keith
> 
> P.S.  Dollars to donuts this thread gets hijacked without changing
> subject lines.

I bet you were thinking bicycling?

-- 





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