Re: [Nbd] Root-on-NBD

[Wouter Verhelst <w@...112...>]

On Fri, Jul 17, 2009 at 11:42:10PM +0200, dsuchod wrote:
> 
> Hi!
> 
> >> Sounds reasonable to me. I'm not sure I understand the need to
> >> disconnect though. What is the issue that occurs if you don't
> >> disconnect?
> >
> > Just that the server doesn't notice the client is gone until the TCP
> > keepalive probes time the connection out. It shouldn't be a major issue,
> > but on resource-strapped servers that serve hundreds of clients, it
> > might be better to avoid it if possible. Also, it's just cleaner to
> > properly disconnect if we know we're going down anyway, and I don't see
> > any downside to doing this (but then, I could be missing something).
> 
> Sounds good! We are using NBD in combination with SQFS on diskless 
> workstations. Often the list of pending server threads does not give
> the full picture of connected clients because they are dead already.
> So it would be nice to have it!
> 
> A bit related question: Would it be possible to survive a suspend-to-
> ram with NBD? Problem would be the dead TCP session after a while ...

There is the -persist option to nbd-client that should make the system
reconnect immediately when the connection drops; you may want to try
using that.

-- 
The biometric identification system at the gates of the CIA headquarters
works because there's a guard with a large gun making sure no one is
trying to fool the system.
  http://www.schneier.com/blog/archives/2009/01/biometrics.html