Fwd: ORBIT-USER: Improved imaging procedures

[Vanessa Frias-martinez]

Thanks Hari! I'll try this...

vanessa

On Wed, 25 Oct 2006, Haris Kremo wrote:

> Vanessa,
>
> Below is a message from Max about more robust way of imaging the nodes.
>
> Hope it helps,
>
> H.
>
> ---------- Forwarded message ----------
> From: Max Ott <max at winlab.rutgers.edu>
> Date: Oct 7, 2006 9:34 PM
> Subject: ORBIT-USER: Improved imaging procedures
> To: orbit-user at winlab.rutgers.edu
>
>
> Folks,
>
> I installed a new version of the nodehandler with which I now
> regularly image the entire grid (or better the approx. 385 nodes which
> boot up properly) in about 16 minutes with almost half of the time
> spent coaxing the nodes to boot up.
>
> As I haven't tested much more than just imaging and also haven't
> installed the new agent on anything but the PXE image, the old
> nodehandler is still there and the new one is called 'nodehandler4'.
>
> Similarly, the new imaging command is called 'imageNodes4'
>
> $ imageNodes4 -h
> Usage: /usr/bin/imageNodes4 [topology] [image_file_path]
>    Example:
>        /usr/bin/imageNodes4 system:topo:all tmp/image-tridencom-test.ndz
>
> It takes two optional arguments, a topology and the image name.
>
> Right now, 'topology' is just a fancy way for defining the list of
> nodes to use, but will in the future include ways to define the
> additional noise injection settings to get us closer to a real
> topology.
>
> There is a new command 'defTopology' (http://tinyurl.com/pcqo8) which
> is almost identical to the way 'defNodes' defines the list of nodes. A
> topology can be saved in its own file and referenced from a defNodes
> command.
>
> For instance, the repository contains a topology containing all nodes
> in the grid. It's URI is 'system:topo:all' and is simply defined as:
>
> defTopology('system:topo:all', [1 .. OConfig['X_MAX'], 1 .. OConfig['Y_MAX']])
>
> Now let's assume you want to use two opposing corner nodes and we hard
> code the grid size to 20x20 (not that I would ever condone hard
> coding). Create a file 'my_topo_diagonal.rb' and add the following
> line:
>
> defTopology('my:topo:diagonal', [[1,1],[20,20]])
>
> Now, you can image those nodes with your image through:
>
> $ imageNodes4 my:topo:diagonal my_image.ndz
>
> The 'defNodes' command in the new nodehandler will accept a topology
> URI as the second argument (selector), but we'll announce that when we
> fully switch over.
>
> Also, please don't use a block with the 'defTopology' command. I
> realized last night that the installed version doesn't properly
> support that - and I don't want to install the fix without testing it
> - not sure when that will happen. In other words, the fancy 'circle'
> example in the wiki page doesn't work, yet. The normal array
> definitions do work, though.
>
> There is still the odd node which sometimes goes deaf during imaging
> and the current imaging script doesn't detect that and as a result
> won't finish, but it happens much less frequently than before and I
> only saw it for > 350 nodes. Hopefully, your experience is similar.
>
> Finally, please note that the default topology behavior is
> 'non-strict', meaning the nodehandler will remove a node from a
> topology or node set if the node doesn't check in after one additional
> reboot. The nodehandler will print a warning message but will then
> continue.
>
> So please check if the nodes skipped are important to you.
>
> WARN Giving up on node n_19_6
>
> Let me know if you have problems and I'll look into it. Don't forget
> to add the experiment ID to any bug report.
>
> Thanks,
>
> -max
>