Port Link down in Distributed Virtual Switch network

[robmc]

I just upgraded from 5.5 to 5.7 and now I'm seeing the following "warning" coming from the Veeam Mgmt pack (i don't see anything in vCenter).
Warning = "Port Link down in Distributed Virtual Switch network"
These events are happening when machines go into and come out of snapshot during vRanger and Symantec NBU VM backups.
Is this an issue I should be concerned about or is it something I should expect to see when VMs go into and come out of snapshot during backups?

[Alec King]

Hi Rob,

Yes we have also seen this error when a VM snapshot is taken for backup purposes.

it is not a 'false alarm' - it does look like VM is briefly offline from the network during snapshot. However it is usually a brief outage.

We're currently investigating the best way to deal with this, in terms of integration with the backup functionality. You can disable the rule of course, but then you could miss genuine outages of network connection for VMs. Best would be to disable only during backup window - we're looking into methods to automate that.

Cheers
Alec

[MB74]

Hi
We also see a lot of these "Port Link down in Distributed Virtual Switch network" warnings but isn't this just because the virtual machines are vMotioned to another host?
The strange thing for me though is that I have set the "CollectorTraceLevel" to Error and still I see a lot of warnings in SCOM??

Regards

Mathias

[Alec King]

Hi Mathias,

If using a distributed virtual switch, I understand the VM should stay connected during a vMotion (unless you are vMotioning to a host which is not configured for the same dVS)

Regarding Collector trace level - this is only for our own internal logging, and should only be changed if advised by our Support.
If you wish to modify the visible alerts in SCOM - you can use standard SCOM overrides for our rules and monitors. For example, just right-click the Alert, and go to Overrides... and choose - disable, override, override for a group, etc.
You can also find all nworks rules and monitors in Authoring section of SCOM console - just clear any Scope and search for 'nworks'

Cheers
Alec

[MB74]

Hi Alec
Thanks for the quick reply.

Ok, great, then I know there is no need for changing the Collector trace level anyway. Overrides is the way to go then.
About the "Port Link down in Distributed Virtual Switch network" it seems to be exactly in time with for example setting one of the hosts in maintenance mode so that all the VM:s are vMotioned, I checked the ports in the Alert description like "The dvPort 1714 link was down" and it matches VM:s being moved.
I have to look into if there are some mismatch in configurations between hosts and vCenter because the hosts are all connected to the same dvSwitches.
Thanks

Mathias

[Alec King]

Ah, OK, not sure what impact Maintenance Mode would have on those alerts. Please let me know what you find out! We always like to remove 'alert spam', and if that rule is firing alerts that are not useful, we'll fix it Thanks!

[IOWDave]

Good Afternoon,

We also see a lot of these alerts and they coincide with either vMotion or VM power on events. We have disabled the alerts for the time being, but if there is a fix then we would be interested in applying it to our environment.

Regards,
Dave.

[Alec King]

Hi All,

Just to update - this alert for 'Port Link Down...' has been proved not useful - it can fire on vMotion, and also on snapshot. We'll be removing it from vNext of nworks MP, and current customers can disable it with an override.

Cheers
Alec