Sure, you'll have a Portage tree, but it will be in you build root.  
here is the way I would set it up

the build root would be under /build, you could also share this over  
nfs too

# cd build
# tar jxvf ~/stage3*.tar.bz2
# cd usr
# tar jxvf ~/portage-latest.tar.bz2
# cd /build

-mounting all the needed directories, binding the root to /build/ 
chroot is only if you want to build packages into it.

# for x in "/sys:/sys" "/dev:/dev/" "/:/chroot"
 > do
 >  mount -o bind $(echo $x|cut -d':' -f1) /build/$(echo $x|cut -d':'  
-f2)
 > done
# mount -t proc none /build/proc
# cat /etc/resolv.conf > /build/etc/resolv.conf
# chroot /build /bin/bash

now you can set your profile, edit your /etc/mack.conf

(chroot) # env-update; source /etc/profile
(chroot) # ROOT="/chroot" emerge <pkg>

for updating you system image use

(chroot) # ROOT="/chroot" emerge <pkg> -uD

you could use world, but it will install the things you may not want.  
you can update the world of the build root /build

(chroot) # emerge --sync ; emerge world -uD

This can all be scripted too, you just neet to make 2 scripts; one to  
start the job and one to work inside the chroot, just change

# chroot /build /bin/bash

to

# chroot /build /start.sh

__________________
Karl Gustav B. Holz
----------
karl@new-aeon.com
----------
http://www.new-aeon.com


On 21-May-07, at 12:27 PM, Ryan Gibbons wrote:

> I believe you will still need a tree either way.
>
> I would just have the master server share it's portage tree over  
> nfs, and then when you update the nodes of the cluster, just mount  
> the nfs share, run your emerge system or world or whatever, and  
> then when you are finished umount the nfs share.
>
> I imagine this could be done easily via scripts, complete with  
> error checking for bad mounts bad emerges etc.
>
> Ronan Mullally wrote:
>> Hi Karl,
>>
>> On Mon, 21 May 2007, Karl Holz wrote:
>>
>>
>>>> Is there a way to run gentoo without a portage tree on each box?
>>>>
>>> yes, if  you setup a build system, using a stage3 tarball, and  
>>> build your
>>> system into a directory. Portage will only be under your /usr/ 
>>> portage and not
>>> into the system image you're building. the good thing about using  
>>> a Stage3
>>> tarball is you can build you system on any linux system, build  
>>> your system
>>> image, tarball the image, deploy and install grub on x86, yaboot  
>>> on Mac PPC,
>>> silo on Sparc64.
>>>
>> How are updates handled?  "emerge -uD <pkg|world>" isn't going to  
>> work
>> without a portage tree, so I presume I'd need to tell each server  
>> which
>> packages need to be updated with "emerge <pkg1> <pkg2> ... <pkgn>"  
>> to have
>> it download them from the binhost?
>>
>>
>> -Ronan
>>