Re: [Qemu-devel] [Question] dump memory when host pci device is used by guest

[Jan Kiszka]

On 2011-10-20 03:22, Wen Congyang wrote:
>>> I didn't read full story but 'crash' is used for investigating kernel core 
>>> generated
>>> by kdump for several years. Considering support service guys, virsh dump 
>>> should support
>>> a format for crash because they can't work well at investigating vmcore by 
>>> gdb.
>>>
>>> crash has several functionality useful for them as 'show kerne log', 'focus 
>>> on a cpu'
>>> 'for-each-task', 'for-each-vma', 'extract ftrace log' etc.
>>>
>>> Anyway, if a man, who is not developper of qemu/kvm, should learn 2 tools 
>>> for
>>> investigating kernel dump, it sounds harmful.
>>
>> Right, that's why everything (live debugging & crash analysis) should be
>> consolidated on the long run over gdb. crash is architecturally obsolete
>> today - not saying it is useless!
> 
> I do not know why crash is obsoleted today. Is there a new better tool to 
> instead
> crash?

I'm not aware of equally powerful (python) scripts for gdb as
replacement, but I think it's worth starting a porting effort at some point.

> 
> At least, I always use crash to live debugging & crash analysis.

Then you may answer some questions to me:
 - Can you attach to a remote target (kgdb, qemu, etc.) and how?
 - Can you use it with latest gdb versions or is the gdb functionality
   hard-wired due to an embedded gdb core in crash (that's how I
   understood Christoph's reply to this topic)

Thanks,
Jan

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