using mclone for mass cloning webconverger workstations

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koenr

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Feb 9, 2012, 2:54:01 PM2/9/12
to Webconverger Users, ste...@walkiers.net
Hi all,
We use webconverger as OS at the moment on 24 computers in several
classrooms. The OS is installed on a small harddisk. We change the
boot parameters without a complete build, following the instructions
on http://webconverger.org/develop/. We dump the isohybrid on a
harddisks using dd.

We were looking into an easier way to upgrade all the workstations to
a newer Webconverger version and came accross Trinity Rescue Kit. This
creates from a bootable CD-ROM an easy netboot server. Using the
mclone tool in the Kit, you can dd harddisks over the network on other
workstations using multicasting (takes about 35 seconds, whatever the
number of workstations).

Sounds all really cool, except that the cloned workstations at first
didn't boot. We noticed that parted doesn't like the iso-hybrid
partition either, so searched the problem in the direction of the iso-
hybrid partition Webconverger resides on.

After some research, we found that you should make the iso bootable
with the -offset 1 option of isohybrid, e.g.

isohybrid -offset 1 custom.iso

It might be good to add something about this to the documentation. It
can also stay here to google up for future reference. I have no idea
if more people want to keep a large amount of Webconvergers up to
date.

Thanks a lot for this great piece of software!
Koen

Kai Hendry

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Feb 9, 2012, 8:44:38 PM2/9/12
to webc-...@googlegroups.com, ste...@walkiers.net
Wow, thanks for writing in Koen. That sounds really really awesome.

So are are your terminals configured to boot PXE by default?

So I guess you don't put your netboot upgrade server online on your
network, unless you want to upgrade?


If you register on the Wiki via
http://webconverger.org/ikiwiki.cgi?do=prefs I can give you admin
rights to edit the Wiki. I can also give you edit rights via a ssh pub
key & git.

It would be great if you could document the whole setup (with photos
:) on the wiki. Else at the very least you could use gist.github.com
and I can merge it in via git.


On the latest blog
http://webconverger.org/blog/entry/Webconverger_11.2_release_notes/ I
do mention I want to deal with the http://webconverger.org/upgrade
problem. I think your solution is great for your setup. Though I can
confidently say most people want it transparent like the Chromium
experience on the desktop.

So I'm planning to add some persistence layer in USB images and use
the existing squashfs as a rsync base for a new update squashfs. I
guess at some point it efficiently downloads the new squashfs in the
background, come release.
Then it scripts the boot command line to boot into the updated
squashfs, and if that for some reason it fails, allow it to fall back
to the old squashfs. A bit like how most distros treat a Linux upgrade
at present. That's the rough idea at present. I like to think of
deployment of customised Webconvergers in terms of a squashfs unit, as
it makes things easy at least for my brain. :}

Thank you for writing in,

koenr

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Feb 10, 2012, 3:25:18 AM2/10/12
to Webconverger Users


On 10 feb, 02:44, Kai Hendry <hen...@webconverger.com> wrote:
> So are are your terminals configured to boot PXE by default?
No, we just change the boot order during upgrade
>
> So I guess you don't put your netboot upgrade server online on your
> network, unless you want to upgrade?
Yes. The netboot upgrade server is nothing more then a CD to boot from
- really convenient. We are thinking of booting over the network for a
screen cast system, since the screens can end up on difficult to
access places (with ladders and stuff ;-) ), but that is for much
later - the backend still has to be build.

I registered in the wiki

I like the save approach for the upgrade process. Would be a great
feature!

Guttorm Flatabø

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Feb 10, 2012, 6:07:21 AM2/10/12
to webc-...@googlegroups.com
On Fri, Feb 10, 2012 at 9:25 AM, koenr <koen.ro...@gmail.com> wrote:
- really convenient. We are thinking of booting over the network for a
screen cast system, since the screens can end up on difficult to
access places (with ladders and stuff ;-) ), but that is for much
later - the backend still has to be build.

As far as I can remember, you can build debian live (and hence Webconverger) for netbooting, or it's a boot option of a kind where you can have your image boot from a simple http:// location.

I tried it with slitaz, I think.

--
Guttorm

Kai Hendry

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Feb 10, 2012, 6:47:16 PM2/10/12
to webc-...@googlegroups.com
On 10 February 2012 16:25, koenr <koen.ro...@gmail.com> wrote:
> I registered in the wiki

Ok, you should have admin rights. Sorry for the delay here.

May I suggest http://webconverger.org/pxenetboot ?


I like the netboot & dd local disk on demand idea.

People do ask for netboot customisations, but traditional netboot
where images are loaded everytime imo sucks big time (far too fragile)
and hence I don't offer it.

Oh btw, did you have to do some special tweaking to enable multicasting?

> I like the save approach for the upgrade process. Would be a great
> feature!

Not sure what you mean by the "save" approach, do you mean "safe"? :)


Cheers!

Kai Hendry

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Feb 10, 2012, 7:00:57 PM2/10/12
to webc-...@googlegroups.com
2012/2/10 Guttorm Flatabø <po...@guttormflatabo.com>:

> As far as I can remember, you can build debian live (and hence Webconverger)
> for netbooting, or it's a boot option of a kind where you can have your
> image boot from a simple http:// location.

I've forgotten about this almost, but yes you could have a netboot
setup, whereby every terminals boot configuration has (something like)
this line:

httpfs=http://192.168.1.1/latest.squashfs

http://live.debian.net/gitweb?p=live-boot.git;a=blob;f=manpages/en/live-boot.7;h=ad6d1d273d319b6474620b28b4faa9438d7238a1;hb=HEAD#l42


Making it download the squashfs IIRC (haven't tested it for ages).
This sort of deployment could be sped up I assume with a transparent
proxy and maybe some "multicasting" switch, but I haven't tried.


I prefer Koen's netboot then dd to disk process at present. Though
maybe I can at revisit with httpfs= with persistency in mind...

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