RE: [Xen-users] Re: Minimal kernel for domU

["Petersson, Mats" <Mats.Petersson@xxxxxxx>]

> -----Original Message-----
> From: xen-users-bounces@xxxxxxxxxxxxxxxxxxx 
> [mailto:xen-users-bounces@xxxxxxxxxxxxxxxxxxx] On Behalf Of 
> Rickard Borgmäster
> Sent: 27 January 2006 15:01
> To: xen-users@xxxxxxxxxxxxxxxxxxx
> Subject: [Xen-users] Re: Minimal kernel for domU
> 
> Jorge Davila wrote:
> > Yes, you can run a 2.4 kernel inside a domU and play with 
> the kernel 
> > options to have the minimal configuration to save memory.
> 
> Are kernels compatible between different xen versions? I copied debian
> 2.4 kernel from xen-2.0 democd and tried to boot is. But I 
> just get Error creating domain: (0, Error)
> 
> Are there any specific intructions for compiling a 
> xen-compatible 2.4 kernel?

I believe that current Xen (3.0, testing, unstable, etc) do not support Kernel 
2.4. It's probably not A LOT of work to make it work, but it's still some work.

However, I have a feeling that the difference in Kernel size wouldn't be THAT 
great - if you minimize the 2.6 kernel, how much bigger is it compared to a 2.4 
kernel? I don't know the answer, but I would think that the KERNEL itself isn't 
that much difference - 2.6 has MORE FEATURES that you can turn on (or off), but 
once you've got the same feature-set, I would think [I'm guessing!] that the 
size difference isn't very much. 

Are you planning on running VERY many domains with small memory footprint? 

Consider that the page-tables for just mapping the memory once in a 1GB system 
takes up one megabyte [or two  megabytes if you use PAE]. Obviously, if you're 
running multiple tasks, each task would have some amount of page-table entries, 
possibly including duplicate ones for user-mode mappings of shared memory 
regions and in some cases also duplicates for the kernel space memory. 

--
Mats
> 
> Best regards,
> Rickard
> 
> 
> _______________________________________________
> Xen-users mailing list
> Xen-users@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-users
> 
> 


_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users