[Pkg-ltsp-devel] root on NBD

[vagrant at freegeek.org]

On Wed, Dec 26, 2007 at 10:36:49AM +0100, Wouter Verhelst wrote:
> I've been lurking on this mailinglist for a while now, and can't help
> but notice that someone here seems to have implemented support for
> running your root filesystem on an nbd device.
 
> I had been planning to add support for this to the nbd-client package
> for a long time, but it simply hasn't happened yet. Since you guys have,
> I'd say it's no longer necessary, either :-)

that would be great to have it integrated into the nbd-client package...

> Could anyone please point me to the stuff that does this root-on-NBD
> support, so that I can integrate it into the nbd-client package?

the support currently requires squashfs and unionfs; the NBD part is
read-only. i've only recently tested it with debian (ubuntu has been
using it for some time):

 bzr get http://bazaar.launchpad.net/~ltsp-upstream/ltsp/ltsp-trunk

(or browseable:
http://codebrowse.launchpad.net/~ltsp-upstream/ltsp/ltsp-trunk/files )

the client-side code is client/initramfs/ltsp_nbd, and is installed into
/usr/share/initramfs-tools and used as a boot script (i.e.
boot=ltsp_nbd).

the server-side code to generate the squashfs image is
server/ltsp-update-image.

server/nbdrootd is run from inetd, and each connection spawns it's own
nbd-server. haven't experimented with using only a single nbd-server for
all connections, though that should be possible.

i've also tested it without using unionfs, though it required manually
tweaking the scripts, and using tmpfs filesystems for the writeable
directories (which ltsp supports).

haven't tested it with ext2 or other filesystems insteaed of squashfs,
but i don't see why it wouldn't work.

live well,
  vagrant