Re: [Libguestfs] Thoughts on nbdkit automatic reconnection

On Wed, Sep 18, 2019 at 01:59:01PM +0100, Richard W.M. Jones wrote: > We have a running problem with the nbdkit VDDK plugin where the VDDK > side apparently disconnects or the network connection is interrupted. > During a virt-v2v conversion this causes the entire operation to fail, > and since v2v conversions take many hours that's not a happy outcome. > > (Aside: I should say that we see many cases where it's claimed that > the connection was dropped, but often when we examine them in detail > the cause is something else. But it seems like this disconnection > thing does happen sometimes.) It turns out in the customer case that led us to talk about this, a Checkpoint firewall was forcing the VDDK control connection to be closed after an idle period.

(The VDDK connection as a whole was not actually idle because data was being copied over the separate data port, but the firewall did not associate the two ports). I believe nbdkit-retry-filter would have helped in this case because reopening the VDDK connection will reestablish the control/metadata connection, and therefore I am looking at an implementation now.