Coda File System

Re: Disconnected operation

From: Jan Harkes <jaharkes_at_cs.cmu.edu>
Date: Wed, 12 Apr 2000 00:09:32 -0400
On Tue, Apr 11, 2000 at 01:52:14PM +0100, Dr A V Le Blanc wrote:
> In reading the documents, it seems to me that there are three
> kinds of disconnected operation: accidental disconnect,
> disconnecting using 'cfs disconnect', and disconnecting by
> shutting your machine down and restarting it in circumstances
> in which no network connection to the servers is possible.

Actually, 'cfs disconnect' simply blocks all outgoing and incoming rpc2
traffic and is therefore equivalent to `pulling the wire'.

> In the first case, I can't see what you can do to prepare for
> it, though I suppose you can run hoard occasionally to make
> certain that as much as you can hold is cached.  Having set
> up the simplest possible hoard file:

Hoard already runs every 5 minutes.

>     add /coda 100:d+
> 
> I tried running hoard on it, then 'hoard walk'; then I gave
> the command 'cfs disconnect'.  To my surprise, I got some
> files, but others gave me an error.  As the cell is still
> fairly small, I was surprised that it wasn't all cached.
> I did have System:Administrator token when I did the hoard walk.

Does "hoard list" show your specified hoard profile?
    hoard clear ; hoard -f <hoardfile>
should get the profile into the client.

Did the walk finish without giving errors?

> Second, I find that after giving 'cfs reconnect' there are
> problems which only disappeared when I shut venus down and
> restarted it.  Is this to be expected?

'cfs reconnect' only clears the rpc2 block, 'cfs checkservers'/'cfs cs'
is probably closer to what you'd expect.

> Finally, I don't see how to start venus when you are completely
> disconnected, and though I thought I saw something about this
> somewhere, I can't find it again.  In other words, if you are
> bringing your laptop away for the weekend, do you have to
> suspend it (which doesn't work on this one), or can you start
> it up and see the coda files while you are away?

You need the hostname/ip-address of at least one of the servers that
were specified when running venus-setup in /etc/hosts. A problem is that
you lose tokens when shutting down venus. The only way around this is to
do:

    clog -tofile /home/xxx/tokenfile

while connected, and

    clog -fromfile /home/xxx/tokenfile

after starting up disconnected.

You need tokens to access files because a disconnected Coda client tries
as hard as possible to provide the same access-restrictions as when it
is connected.

Jan
Received on 2000-04-12 00:11:18