[Pkg-xen-devel] Re: Bug#390862: -bigmem version of xen kernels is really needed

Ralph Passgang ralph at debianbase.de
Tue Dec 12 15:59:13 CET 2006

Am Dienstag, 12. Dezember 2006 10:54 schrieb Nikita V. Youshchenko:
> What about idea not to *add* pae versions of xen kernels, but to *replace*
> non-pae versions with pae versions?

I don't think that debian should ship only pae-enabled kernels, because this 
has some disadvantages:

- the slowdown, even if it's minimal, I personaly don't want to get forced to 
use it.

- only pae-enabled system can use xen in 32bit mode, cpu's without pae cannot 
use xen at all! Not every cpu/bios is able to handle pae. 
(see "cat /proc/cpuinfo" for your cpu and check your bios settings if you are 
not sure).

- I had some trouble with pae on standard server hardware (in combination with 
xen) in the past. I think pae can make your system less stable (in rare 

My personal conclussion: pae is only a dirty hack. use it if you must, 
otherwise a non pae-enabled kernel/os is better.

I think debian should normal AND pae-enabled kernels, or maybe have the kernel 
decice that on boottime automaticly (if that's possible).

ah, and I don't get the "distribution compatibiltiy" point.
If your domU system is debian based, then you will use the non-pae kernel from 
etch and all your domUs also can use the same kernel. It doesn't matter if 
domU is also debian or fedora or something else, they should work with a 
debian kernel...
The same is true for a dom0 based on fedora and debian as domU. Use the same 
kernel (the one that gets shipped with the dom0 distribution) and use that 
for your debian domUs, too.

For compatibility it's more important that every distribution uses udev (for 
example) and not the depricated hotplug system.

just my 5 cent ;-P


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