On Wed, 16 Oct 2002, Stephen J. Turnbull wrote:

> >>>>> "Kevin" == Kevin Atkinson <kevin_at_atkinson.dhs.org> writes:
> 
>     Kevin> Instead of treating partly retrieve files as file fragments
>     Kevin> or blocks why not simply treat them as that.  That is
>     Kevin> instead of insisting upon retrieving the whole file simply
>     Kevin> retrieve the part requested and mark the file as partly
>     Kevin> retrieve on the client and just the client.  The server
>     Kevin> does not need to worry about which parts the client has, it
>     Kevin> only has to worry that it has some parts thus simplifying
>     Kevin> things greatly.
> 
> Not really; the server already does not worry about what the client
> has (the client may have gone disconnected, remember).  

How has the client gone disconnected?  I never said that.

> The complexity
> Jan is describing is entirely client-side.  The problem is that
> programs expect "reliable stream" semantics as well as "random access
> block device" semantics from files, and your scheme emphasizes random
> access to blocks at the expense of stream reliability.  

What exactly do you mean by "reliable stream"?

> Consider: with current Coda design you can drive a CD-RW from an image 
> on the Coda FS (assuming a pretty unloaded or very fast system).  With 
> your design, I think not.

Actually SMB over 100 GB network works just fine for for burning a CD 
image over the network.  I have done it several times before.

> From your requirements, it sounds to me like what you are describing
> as ideal is something like WebDAV

I will have a look but I think I will stick with my current system of 
manually copying files around.

-- 
http://kevin.atkinson.dhs.org