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

On Sat, May 22, 2010 at 06:47:19PM -0700, Scott Feldman wrote: > On 5/22/10 6:24 PM, "Dave Allan" <dallan(a)redhat.com&gt; wrote: > >>>> 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. > > What can we do in libvirt to provide async status of port-profile > association? How could an aynsc status be reported to the user via libvirt? > In the virt-manager GUI, for example, on the details sheet for the NICs, can > we display the status of the backing virtual port? Kind of like the status > on the basic details overview sheet. Actually, if we could display the > other virtual port settings like port-profile name of VSI-* tuple along with > status, then the user would have some good info to start troubleshooting. It's not impossible to do what you're suggesting here, but what's the benefit? Is it a problem to poll for even 10 or 20 seconds?