How do I do a COLD Reboot on FreeBSD?

Billy Newsom smartweb at
Mon Jan 31 10:53:06 PST 2005

Jerry McAllister wrote:
> 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.

No, I said a cold reboot.  That's the term for a reboot which runs the entire 
POST, counts memory, etc.  The screen looks identical to a cold start or cold 
boot.  We all know what the warm reboot means -- that's when many parts of 
the POST are skipped.  Windows uses a cold reboot, for example, when you 
click "Restart" on the Shutdown menu.  FreeBSD does a warm reboot using the 
reboot command.  The warm reboot may save thirty to sixty seconds over the 
cold reboot.  A warm reboot typically skips the memory check and does a 
cursory check of hard drive parameters, etc. to save time.

If you use a PC DOCTOR disk and tell it to reboot, it will do a cold reboot. 
  When you flash your BIOS from DOS, it will usually do a cold reboot when it 
exits.  When you save changes and reboot from the BIOS setup screen, it will 
do a cold reboot.  Many other examples are possible.

What I tried to explain is that this PC crashes on the subsequent boot if a 
warm reboot is performed by FreeBSD.  But if I could perform a cold reboot 
every time, this would solve the issue.  A cold reboot is not the act of 
"shutting the power off and turning it back on."  That is called a power 
cycle and it is obviously manual.  A cold reboot is done by a special 
software command.

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

No, it fails.

> 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.

The revelation is at hand.

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