[fedora-virt] febootstrap purpose status

[Richard W.M. Jones]

On Sat, Jul 25, 2009 at 02:17:38AM -0500, Paul Lambert wrote:
> Can I get an explanation of the targeted users of this distro?

There's a bit of confusion in your post, so to get some facts out the
way first:

(a) febootstrap is a shell script that runs yum as non-root, and comes
with some other shell scripts which can trim the fat from Fedora, but
they are not essential to its purpose which is just to run yum without
needing root privileges.

(b) It's only designed for people who want to run yum as non-root.
Specifically this is a requirement for building and running
libguestfs.

(c) febootstrap installs standard yum-based distributions, ie.
Fedora, Red Hat Enterprise Linux, CentOS and probably others.

> The  
> reason I ask is twofold. 1) I am looking for a bare metal OS to base  
> real time control on and 2) I believe that VMware has it right with  
> respects to hypervisor architecture.  Again,  a bare metal host with the  
> actual guest OS running the interface and application code.
>
> My current configuration using Fedora 11 as the host and running WinXP  
> as a guest is what I term the "workstation" mode.  The host OS still  
> performs user interface and file storage functions for users.  This is  
> the same as using VMware workstation.  The full hyperviser mode would be  
> a minimum Fedora build that allows a command line only interface.  No  
> graphics libraries or other user intereface systems.  This is  
> essentially ESX.  I would create a Fedora 11 appliance and a WinXP  
> appliance and import these through command line instructions.  (Or  
> better yet, Fedora would release a distro that included installing the  
> bare metal version and the full Fedora appliance.)  The Fedora guest  
> then could connect back to the bare metal host to perform monitoring and  
> VM management function (oVirt). 

Honestly I think what you're looking for _is_ the hypervisor component
of oVirt.  This component at the moment isn't built with febootstrap
(it uses some kickstart stuff that has to run as root), but it's on
their roadmap to use febootstrap or something like it, post-F12.

> I want this on my laptop.  Upgrading the host while it is also serving  
> as a workstation is too risky and a lot of work to perform OS testing  
> and evaluation.  It's too easy to copy out one's guest VMs and reload or  
> upgrade the host.  Then when this activity is complete just reinstall  
> the original host and VM appliances.  Backup and restore are much easier  
> as well. 
>
> The last I saw on the febootstrap size I believe it was just under 20  
> mb.  This still seams extremely large for a bare metal system.  I need  
> the Fedora filesystem with KVM and the hardware driver library.  How  
> small can we go?  I would like to try this.

Honestly, if you want libvirt, KVM etc. you won't get much smaller
than 100 MB (filesystem) + ~ 200 MB (RAM required by the host).

Fedora just isn't very well suited to building minimal versions like
that.  If the above numbers are too big, then you should look at a
specific minimal Linux distro.  For why we didn't use that in
libguestfs, see:

http://rwmj.wordpress.com/2009/03/20/why-not-use-a-minimal-distribution/

Rich.

-- 
Richard Jones, Emerging Technologies, Red Hat  http://et.redhat.com/~rjones
libguestfs lets you edit virtual machines.  Supports shell scripting,
bindings from many languages.  http://et.redhat.com/~rjones/libguestfs/
See what it can do: http://et.redhat.com/~rjones/libguestfs/recipes.html