[Users] Pxeboot

Wed Feb 8 22:03:42 UTC 2012

On Wed, 2012-02-08 at 13:46 -0800, Li, David wrote:
> Mike,
> 
> If I understand this correctly, today I should be able to pxeboot and
> nfs mount the root fs from a remote server.  Apart from setting up the
> pxe stuff, I 'd have to populate the ovirt node root fs on the server
> - perhaps steal it from a disk install.  In other words I am concerned
> about the point from which the kernel starts to execute /init script
> (in the initramfs) to the point /init is able to mount the final root
> fs from a remote server. 

No, there is no way to set this up currently in ovirt-node.  You could
install using a remote iscsi lun if you have a hardware iscsi HBA, but
there isn't a way to mount a remote nfs share as the root fs.  

Supporting a remote NFS share as the root fs isn't even something that
requested as an RFE at this point or on the roadmap as far as I'm
aware.  

It sounds like what you're really looking for is a shared root fs that
multiple hosts could use.  This is something that we will probably look
into eventually, but it's not on the immediate roadmap.  

> 
> I understand the challenge you talked about.  But this is the very
> first step.  I looked at the archipel but couldn't figure out where it
> stands on this. No one from their mailing list responded either. 

The changes that the archipel people made are here:

https://github.com/primalmotion/archipel-node

I've also reduced to a single commit that I've uploaded to gerrit.

http://gerrit.ovirt.org/#change,1738

Mike

> 
> David
> 
> >-----Original Message-----
> >From: Mike Burns [mailto:mburns at redhat.com]
> >Sent: Wednesday, February 08, 2012 11:12 AM
> >To: Li, David
> >Cc: users at ovirt.org
> >Subject: Re: [Users] Pxeboot
> >
> >On Wed, 2012-02-08 at 10:51 -0800, Li, David wrote:
> >> Mike,
> >>
> >> I 'd like to understand what it takes to do this.
> >> Do we need a special initramfs for oVirt node to help with the stateless
> >pxeboot? Some tools like Dracut and Dracut-network to create such an
> >initramfs?
> >
> >There are a few things needed, many of which are discussed on the
> >Node_Stateless wiki page.  There was some work done by some other people
> >to get a stateless node working for archipel that I haven't pulled back into the
> >node yet.
> >
> >The biggest challenge is that pieces of the oVirt project require there to be
> >persistent storage locally.  For example, when you register a node with the
> >engine, a manual step is required to approve the node.  After this manual step,
> >some certificates are copied locally into the node and stored.  That way, the
> >node can immediately identify itself with the engine and start working with no
> >need to identify itself.
> >
> >To solve this problem, we need to either 1.  remove the need to store stuff
> >locally 2.  provide some way to package up this config and store it somewhere,
> >then retrieve on boot 3.  embed some sort of key or certificate in the pxe
> >image that allows the engine to know that this valid machine and
> >automatically approve it.
> >
> >The archipel stuff doesn't deal with all of that.  My understanding is that they
> >just start using whatever clients identify themselves.
> >
> >I do have a task on my plate to pull the stuff from archipel-node back into
> >ovirt-node and incorporate what they've done into the overall stateless
> >design.
> >
> >Mike
> >
> >>
> >> David
> >>
> >> >-----Original Message-----
> >> >From: Mike Burns [mailto:mburns at redhat.com]
> >> >Sent: Wednesday, February 08, 2012 10:35 AM
> >> >To: Li, David
> >> >Cc: users at ovirt.org
> >> >Subject: Re: [Users] Pxeboot
> >> >
> >> >On Wed, 2012-02-08 at 10:24 -0800, Li, David wrote:
> >> >> Hi Mike,
> >> >>
> >> >> I read the oVirt node  Wiki and had an impression it's not ready in 2.3 yet:
> >> >http://ovirt.org/wiki/Node_Stateless .
> >> >>
> >> >> Ok, I saw that tool in the ISO. Let me dig in to how to use it.
> >> >> The real question now is if I can nfs mount the the real rootfs
> >> >> which would
> >> >also be on the TFTP/DHCP server in the final pxe booting stage.  Is
> >> >that something you are doing too?
> >> >
> >> >Ok, I think I see where the confusion is now.  We support using
> >> >pxeboot to install to a local disk, but not full stateless booting
> >> >and pulling the configuration from elsewhere.
> >> >
> >> >It won't really be feasible to so something like this until we have
> >> >stateless support worked out, but you're welcome to work with us to get it
> >working.
> >> >
> >> >Mike
> >> >
> >> >>
> >> >> David
> >> >>
> >> >> >-----Original Message-----
> >> >> >From: Mike Burns [mailto:mburns at redhat.com]
> >> >> >Sent: Wednesday, February 08, 2012 10:11 AM
> >> >> >To: Li, David
> >> >> >Cc: users at ovirt.org
> >> >> >Subject: Re: [Users] Pxeboot
> >> >> >
> >> >> >On Wed, 2012-02-08 at 09:53 -0800, Li, David wrote:
> >> >> >> Since oVirt node doesn’t support pxeboot in the current release,
> >> >> >> does anyone know if I can use RHEV-H to pxeboot and nfs mout the
> >> >rootfs?
> >> >> >
> >> >> >Where does it say that ovirt-node doesn't support pxe boot?  I use
> >> >> >PXE in my testing.  I haven't heard of any issues with PXE either.
> >> >> >
> >> >> >The livecd-iso-to-pxeboot script in livecd-tools will create the
> >> >> >initrd and vmlinuz files for you to import into your PXE server.
> >> >> >
> >> >> >Mike
> >> >> >>
> >> >> >> David
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >>
> >> >> >> _______________________________________________
> >> >> >> Users mailing list
> >> >> >> Users at ovirt.org
> >> >> >> http://lists.ovirt.org/mailman/listinfo/users
> >> >> >
> >> >>
> >> >> _______________________________________________
> >> >> Users mailing list
> >> >> Users at ovirt.org
> >> >> http://lists.ovirt.org/mailman/listinfo/users
> >> >
> >>
> >> _______________________________________________
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> 