Maintaining Xen with FAI - Questions

[Mario Bischof]

>> Hello,
>>
>> I've got several Questions about using FAI to install a Xen virtual
>> Domain.
>>
>> - First of all, what did you use to make custom kernels? I tried to
>> use make-kpkg for generating xen dom0 and domU kernels, for the dom0
>> kernel it works fine, I am using the xen hypervisor provided by the
>> debian repository, that works ok together with homemade Dom0 linux-
>> kernel.
>> Please correct me if I already have done something stupid at this  
>> time.
>>
> I'm using a custom built xen kernel as well, because Debian kernels  
> for xen
> lack pae support :-(
>
>> - If I install the whole xen-system by apt-getting it, i can start a
>> FAI Installation with the initrd provided by the deb package and the
>> xenu kernel i generated by myself, of course i have to install my
>> domu kernel over the xen system installation, also not very clean,
>> but i dont know how to build a .deb-package out of the xen-utils or
>> the hypervisor when i compile it from source.  But if i try to use
>> ONLY my domu kernel it doesnt start. XEND.log says "domain has
>> crashed".  Building deb-pkgs from xen-source seems pretty advanced to
>> me, because there are several make targets, dom0, domu and xen-utils
>> with hypervisor,so how did you guys manage this?
>>
> Why don't you use the packages provided by Debian? Here we've got:
>
> root at wasp:~# dpkg -l | grep xen
> ii  libc6-xen                               
> 2.3.6.ds1-7                     GNU C Library: Shared libraries  
> [Xen version
> ii  linux-xen0-2.6.18-686xenbigmem         F. 
> 1                             Linux xen kernel binary image for  
> version 2.
> ii  xen-hypervisor-3.0-unstable-1-i386-pae 3.0-unstable 
> +hg11561-1          The Xen Hypervisor on i386-pae-class
> ii  xen-utils-3.0-unstable-1               3.0-unstable 
> +hg11561-1          XEN administrative tools
> ii  xen-utils-common                        
> 3.0.3-0-1                       XEN administrative tools - common  
> files
>
> (System is entirely from Debian/etch)
>
>> - Is there any essential support I have to setup in my domu kernel to
>> get FAI to start running without an initrd?? I've checked there is
>> already NFS support built into my domU-kernel. But what else do i
>> need to be ready to use fai with xen?
>>
> Network, disk, NFS should be about it...
>
>> - Do you use seperate kernels for dom0 and domU? the debian pkg from
>> official server installs one kernel for both. What are the advantages
>> of using just one for both purposes?
>>
> The same kernel everywhere... The advantage of using one for both  
> should be
> obvious: It takes a lot more time to build and maintain two  
> variants of your
> kernel. And I don't know about any disadvantages...
>

I always thought using custom xen kernels is  better for security? So  
you can do a bit kernel-hardening and just put the things in Dom0 and  
DomU you want and not just everything that seems to be used by the  
common debian user (?) . Well, does the standard xen-kernel from  
debian also provide HVM support for using win xp? does it include tun/ 
tap device support for creating openVPN domains?
I'm still not very familiar with the thought of using this .deb-pkg  
while having the opportunity to build it myself and having the power  
over what goes into my kernel and what doesnt. I want to build  
servers for day-to-day use, I just want to have a little bit more  
control :-)

Would be still interesting to know how to build all these things from  
source.

How did you get your custom kernel to run with fai?

Thanks,

Mario