add support for writeable read-only nfsroot through unionfs

[Václav Šmilauer]

I am willing to implement this and since I don't know a better place to discuss
how to do it, I post it as an enhancement request.

I would like to serve multiple ubuntu fat clients sharing one NFS root. The root
would be ro, being unioned with writeable tmpfs getting changes to /etc, /tmp,
/var, other dirs being ro. Changes would be lost at shutdown. What am I about to do:

1. use the kernel command-line option saying that the nfsroot is ro.
2. have a hook for including unionfs module (and userspace utils, if needed)
3. put a simple script /scripts/nfs-bottom that would make the union of a rw
tmpfs with /etc, /tmp and /var. (If there is another kernel cmdline option to do
this, it could perhaps be included in the initrafs-tools discribution?)
(4.) Custom init script on the real root that would generate xorg.conf for the
client it runs on, as all the rest is pretty much autodetected.

AFAIK something very similar is used for the live CD, are there some pointers
for this?

Regards,

Vaclav Smilauer

[laga (laga)]

I'm working on something very similar: public / on nfs and client-specify overlays using unionfs. If you still want to get this going, i can give you some pointers. Most of the work is already done. Since Ubuntu has bulletproof-x, it shouldn't be too hard to create a new xorg.conf.

Regards,

Michael

[laga (laga)]

Just found bug #85145

Should be enough to get you started.

[John Kim (kotux)]

 Thank you for taking the time to report this bug and helping to make Ubuntu better. We are sorry that we do not always have the capacity to look at all reported bugs in a timely manner. There have been many changes in Ubuntu since that time you reported the bug and your problem may have been fixed with some of the updates. It would help us a lot if you could test it on a currently supported Ubuntu version. When you test it and it is still an issue, kindly upload the updated logs by running apport-collect <bug #> and any other logs that are relevant for this particular issue.