Re: dump device

[Zone]

This question went around a few years ago. In the end, due to the
difficulty in making anything safe with all possible configurations it
kind of died out. Trying to get the data onto disk after a major problem
is risky. 

Many other systems have hardware assist in the dump routines i.e. code in
ROM or protected memory. Some systems may even have dedicated processors
to monitor the system and perform the dump in the event of a fault.

With some of the new high speed communications options (for example USB or
FireWire) it could be a good project to stream a dump to a debuging
station but even then you cannot be sure of what you are going to get if
the crash involves the normal drivers for that hardware.

I still like a monitor program that is loaded into memory at kernel load
time that is given control in the event of a panic. If it knew how to
handle a text console, the keyboard and the floppy in a manner completely
independent of the kernel it could be used to help debug a crash by
producing a mini-dump to the floppy device.

  

On Fri, 30 Jun 2000 [e-mail] wrote:

> 
> 
> no, for the simple reason that if the system is crashed,
> it's unsafe to attempt _any_ kind of work, including IO
> to a dedicated device.
> 
> -- But here also we still try to write something to /var/log/messages
> -- Some kind of traceback, and system is still unsafe !!
> 
> there's at least one patch, not in the mainstream kernel,
> that does crashdumps.
> 
> 
> 
> how can you trust any IO when the system is corrupt?
> 
> -- But Aix have such a facility. Then how does Aix do this stuff ?
> 
> 
> 
> 
> 
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to [e-mail]
> Please read the FAQ at http://www.tux.org/lkml/
>