Re: Re: Adding PTE Flag during Page Fault

[Joe Laws <jlaws@andrew.cmu.edu>]

Thanks for the suggestion Keir, unfortunately my kernel lacks the option
for kexec, despite the fact that all the source files are included. 
Anyway, I was able to get the information I need by passing certain args
to the xen kernel via grub:

kernel /xen.gz noreboot console=vga vga=keep xencons=tty

Using this output I managed to get my stuff working this morning also. 
I was surprised to learn that of the ~90K pages saved (for a 380MB
memory image) only ~1500 are needed for the system to start up and
continue running.  Granted every time something is done another 10-20
pages get loaded, the fact that less than 2% only need to be present to
start the VM again is crazy.  This means that only ~6MB of the memory
image needs to be present to resume. 

-Joe

Keir Fraser wrote:
>
> On 14/4/07 22:29, "Joe Laws" <jlaws@andrew.cmu.edu> wrote:
>
>   
>> Now it just causes Xen to crash and my computer to reboot.
>> Unfortunately I can only see the output to the log by doing xm dmesg,
>> which gets cleared on every reboot.  Are there any efficient techniques
>> to get the latest xm dmesg output to file before the system crashes?
>>     
>
> You can use kdump (basically chain boot into a special crash-dump Linux
> kernel with block or net drivers which will scrape memory for things like
> Xen heap and Xen logging output).
>
>  -- Keir
>
>
>
>