Hello all,

My name is Mor, I am from the RHV networking team.

I am experiencing an issue with PCI device slot ID's and network interface names that appear sometimes on my environment. I was advised to contact this mailing-list in hope to get explanation or possible solution for this issue.

The issue is the following:

On our oVirt 4.2 master environments, we create VM's from sealed template that has only one vNIC attached to the ovirtmgmt network. Sometimes, and now I am able to fully reproduce it on a specific VM, when I add new vNIC, it gets allocated with lower PCI slot id, compared to what is allocated on the default vNIC. For example, original one got slot id: 0xA, and newer one got slot id: 0x3. 

The order of slot ID's affects the network 'ethX' naming on the guest OS (RHEL 7.4).  Lower slot ID's gets numbered from 0 to N. The problem is that if we had configuration for DHCP on 'eth0' and the order is changed, we can lose connectivity to the host.

Can you please share your opinion on this issue?

Mor Kalfon
RHV Networking Team
Red Hat IL-Raanana
Tel: +972-54-6514148