Re: [libvirt] [RFC] [PATCH 3/3 v2] vepa+vsi: Some experimental code for 802.1Qbh

>> Mostly I'm concerned about the failure case: how would the user know >> that something has gone wrong, and where would information to debug >> the problem appear? > > Think of it as equivalent to waiting to get link UP after plugging in a > physical cable into a physical switch port. In some cases negotiation of > the link may take on the order of seconds. Depends on the physical media, > of course. A user can check for link UP using ethtool or ip cmd. > Similarly, a user can check for association status using ip cmd, once we > extend ip cmd to know about virtual ports (patch for ip cmd coming soon). That's the way I was thinking about it as well. The difference I see between an actual physical cable and what we're doing here is that if you're in the data center and you plug in a cable, you're focused on whether the link comes up. Here, the actor is likely to be an automated process, and users will simply be presented with a VM with no or incorrect connectivity, and they will have no idea what happened. It's just not supportable to provide them with no indication of what failed or why.