On 5/22/10 11:34 AM, "Dave Allan" <dallan@xxxxxxxxxx> wrote: > On Sat, May 22, 2010 at 11:14:20AM -0400, Stefan Berger wrote: >> On Fri, 2010-05-21 at 23:35 -0700, Scott Feldman wrote: >>> On 5/21/10 6:50 AM, "Stefan Berger" <stefanb@xxxxxxxxxxxxxxxxxx> wrote: >>> >>>> This patch may get 802.1Qbh devices working. I am adding some code to >>>> poll for the status of an 802.1Qbh device and loop for a while until the >>>> status indicates success. This part for sure needs more work and >>>> testing... >>> >>> I think we can drop this patch 3/3. For bh, we don't want to poll for >>> status because it may take awhile before status of other than in-progress is >>> indicated. Link UP on the eth is the async notification of status=success. >> >> The idea was to find out whether the association actually worked and if >> not either fail the start of the VM or not hotplug the interface. If we >> don't do that the user may end up having a VM that has no connectivity >> (depending on how the switch handles an un-associated VM) and start >> debugging all kinds of things... Really, I would like to know if >> something went wrong. How long would we have to wait for the status to >> change? How does a switch handle traffic from a VM if the association >> failed? At least for 802.1Qbg we were going to get failure notification. > > I tend to agree that we should try to get some indication of whether > the associate succeeded or failed. Is the time that we would have to > poll bounded by anything, or is it reasonably short? It's difficult to put an upper bound on how long to poll. In most case, status would be available in a reasonably short period of time, but the upper bound depends on activity external to the host. > 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). -scott -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list