Re: What's left over.

[Hugh Dickins]

On Fri, 1 Nov 2002, Linus Torvalds wrote:
> On Fri, 1 Nov 2002, Joel Becker wrote:
> > 
> > 	I always liked the AIX dumper choices.  You could either dump to
> > the swap area (and startup detects the dump and moves it to the
> > filesystem before swapon) or provide a dedicated dump partition.  The
> > latter was prefered.
> 
> Ehh.. That was on closed hardware that was largely designed with and for
> the OS.
>... 
> In other words: it's a huge risk to play with the disk when the system is
> already known to be unstable. The disk drivers tend to be one of the main
> issues even when everything else is _stable_, for chrissake!
> 
> To add insult to injury, you will not be able to actually _test_ any of 
> the real error paths in real life. Sure, you will be able to test forced 
> dumps on _your_ hardware, but while that is fine in the AIX model ("we 
> control the hardware, and charge the user five times what it is worth"), 
> again that doesn't mean _squat_ in the PC hardware space.

I dealt with crash dumps quite a lot over 10 years with SCO UNIX,
OpenServer and UnixWare: which were addressing the PC market, not
own hardware.

It's a real worry that writing a crash dump to disk might stomp in the
wrong place, but I don't recall it ever happening in practice.  But
occasionally, yes, a dump was not generated at all, or not completed.

Of course, you could argue that SCO's disk drivers were more stable :-)
which might or might not be a compliment to them.

Hugh