Re: How do I do a COLD Reboot on FreeBSD?

From: Jerry McAllister (jerrymc_at_clunix.cl.msu.edu)
Date: 01/31/05

  • Next message: Mark Ovens: "Re: Booting FreeBSD-5.3 from NTLDR"
    To: billy@nlcc.us (Billy Newsom)
    Date: Mon, 31 Jan 2005 10:50:55 -0500 (EST)
    
    

    >
    > Jerry McAllister wrote:
    > >>I need to do a cold restart. I've looked through a lot of docs, and I
    > >>can't
    > >>seem to find this out. The computer I am working with seems to no longer
    > >>enjoy a warm reboot (like "shutdown -r now" or "reboot") but I'm pretty
    > >>sure
    > >>it will do cold reboots fine. Is there a port, or is the shutdown command
    > >>hackable for this, or what?
    > >>
    > >>I remember many computers in bygone years which had this problem. It was
    > >>pretty common back in the 90's it seems like. Computers would reboot and
    > >>act
    > >>weird using CTRL-ALT-DELETE, but work fine when powered off and on.
    > >
    > >
    > > FreeBSD is pretty good about doing a very clean reboot as far as the OS
    > > is concerned. But, it is possible that some devices don't clean up well
    > > in ways that are out of FreeBSD control. So, a "cold boot" can be a
    > > good idea in some circumstances.
    > >
    > > To do this, do a 'shutdown -h now' or a 'shutdown -p now' if your
    > > hardware supports the -p and you have it set up. Choose your own
    > > time of delay for 'now' if you have other people on the machine.
    > >
    > > If you did the '-h' or the '-p' didn't turn off the power, then
    > > at the "press any key to reboot" prompt, turn off the power.
    > > Then, unplug the power source and let it set for a few minutes to let
    > > any charge dissipate. This can be important because the capacitance
    > > in some of the devices including the power supply can provide just
    > > enough charge to keep them from reloading if that is their inclination
    > > and you lose the effect you are looking for. You should also unplug
    > > the network connection and any external devices that have their own
    > > power supply.
    > I know that this is all very good advice and information from the shutdown
    > man page and good stuff about the nature of capacitors, but all of this is
    > known to myself and unfortunately not useful... The shutdown -p does
    > essentially a different thing (and one time it caused the freeze problem to
    > disappear.) but this also does not work. I don't want to shut the computer
    > off, anyway, I want it to reboot back to FreeBSD remotely if need be.
    >
    > And so far, the halt command (or its shutdown -h equivalent) is not what I
    > want, either. If I press a key to reboot, I get the same issue anyway.
    > There's a remote possibility that the halt code is causing the freeze up,
    > because FreeBSD 4.7 did not have this problem. I'm not confident whether the
    > machine broke or the new 5.3 code broke, so I won't speculate which. I just
    > need the reboot code.
    >
    > ...
    >
    > > After a sufficient time drain capacitance - I usually go to the bathroom
    > > or go get something to drink to kill a few minutes - , then just plug
    > > it all back in. Plug in the network cable and any external devices first
    > > and then the power cord and turn it on and let it boot.
    >
    > It's not the capacitors, but perhaps some strange bug in the BIOS or
    > something, I guess. The issue that I'm highlighting is that when a floppy
    > program does a cold reset of this machine, the system (re)boots normally.

    Well, I guess I completely do not understand what you are asking.
    >From anything I can get from what you write here, its behavior is
    normal and expected. What is the problem and what are you trying
    to fix or to get it to do?

    A cold boot - which is what you ask about in your original post - is
    a boot all the way up from a powered off machine as far as I know.
    So, all I did was explain how to get what you asked for in the post.

    Another small guess - are you looking for 'shutdown -r now' by
    any chance?

    If you want something else, you will need to explain that. Who knows
    if anyone will know what to do about that - at least not until you
    reveal what it is.

    ////jerry

    >
    > As a side note, I have run this machine through the ringer trying to discover
    > any hardware errors. The memory is now EDO ECC (it had been something else)
    > and the problem persists. I have run diagnostics, memtest86, etc. Futile.
    > The cold reset code exists somewhere. Anybody?
    >
    > Billy
    > >
    > > Voila, you have gone from warm to cold to warm again.
    > >
    > > ////jerry
    > >
    > >
    > >>The computer I've got actually fails a memory test during the warm reboot.
    > >>This freezes it. I have to power cycle the machine. And then, the computer
    > >>performs a warm restart, bypassing its memory checks! One more power cycle
    > >>laster, it will boot normally. If I don't do this last reboot, the FreeBSD
    > >>boot loader or the beginning of the kernel boot crashes very early. It's
    > >>stable otherwise on a cold reboot.
    > >>
    > >>Thanks,
    > >>Billy
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  • Next message: Mark Ovens: "Re: Booting FreeBSD-5.3 from NTLDR"

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