Coda File System

Re: Remote boot vanaf Coda

From: Dick Kniep <>
Date: 08 Jul 2003 22:35:07 +0200
Hi Jan, 

On Mon, 2003-07-07 at 23:37, Jan Harkes wrote: 
> On Mon, Jul 07, 2003 at 10:45:47AM +0200, Dick Kniep wrote:
> > 1. We would like to use Coda instead of NFS to boot from. Is that
> > possible? (I doubt that, because Venus is a standard application, which
> > should be loaded BEFORE the system has started....)
> Considering that you'll need a local disk for the Coda client cache
> anyways, one way would be to install a minimal boot/root setup on each
> client and keep most of the disk available for the cache.
We would prefer NOT to have a disk in the clients 

> Another solution would be to have the venus binary in the initrd image
> that is downloaded along with the kernel. But you still need to somehow
> set up the local disk to be used as a Coda cache. And I'm not really
> sure how you want to deal with persistence across reboots.
So we could setup a RAM-disk. But persistence is a must.... If you
shutdown the system, could you force venus to write to the server? And
how much time takes it before the server is synchronized with the RAM
disk? In that case you only loose data if you get acrash (which is very
rare :-)

> It is possible to run venus with VM instead of RVM and place the local
> cache on a tmpfs filesystem. I used that on an iPaq to minimize writing
> to flash, but as it provides no persistency it will lose all not yet
> reintegrated changes across a crash or reboot.
That is not acceptable 

> > 2. If NOT possible, can we mount a Coda partition thru NFS? 
> > 
> > If the second is also not possible, are there any alternatives?
> It is possible, I used the userspace nfsd before, but never tried the
> knfsd. NFS doesn't like to export a 'network filesystem', possibly to
> avoid recursively exporting itself, and needs a special option like
> --reexport or something.

Then I think we'll go for the NFS setup where the servers are mirrorred
thru Coda. That way we'll avoid the SPOF, and have a (relatively) simple
setup for the remote boot. 

NFS is much cruder, because it directly writes to disk. in this case,
that is exactly what we want...

Thanks for the advice,
If you have any more...

Dick Kniep
Received on 2003-07-08 16:31:04