[OpenAFS] 'diskless' clients with AFS in Linux initrd

Jeffrey Hutzelman jhutz@cmu.edu
Fri, 14 Dec 2001 11:43:22 -0700 (MST)

On 14 Dec 2001, Cees de Groot wrote:

> ('diskless' means 'without any local state' :-))
> I was wondering whether it was doable/feasible/sensible or downright stupid to
> use Linux' initrd feature to:
> - start AFS from the initrd disk
> - have a dummy root filesystem on the local disk, with just symlinks into
>   AFS (some of them made during boot so you point to the /etc for the correct
>   node, etcetera);
> in order to obtain a configuration with no considerable local state. Has
> anyone tried this? It should work (anything goes with initrd :-)), but I
> wonder how much work it is to make it work. 

Offhand, this seems like a bad idea.  Virtually all programs in a running
Linux system are demand-paged from disk.  Imagine for a moment what would
happen if the fileserver on which init lived went away, thereby preventing
init from being paged in.

I also have no confidence at the moment that AFS still works in the initrd
environment.  While an initrd is in use, kernel startup has not completely
finished.  I used to support installing RedHat systems via AFS, but had to
stop doing that with RH7.1 when AFS stopped working in the initrd

-- Jeffrey T. Hutzelman (N3NHS) <jhutz+@cmu.edu>
   Sr. Research Systems Programmer
   School of Computer Science - Research Computing Facility
   Carnegie Mellon University - Pittsburgh, PA