Hi,
I had a dvSwitch configured with four uplinks, they were named and configured in the following manner
dvUplink1 - Connects to LAN NIC with several VLANs
dvUplink2 - Connects to LAN NIC with several VLANs
dvUplink3 - Not connected
VMotion - Connects to dedicated vmotion NIC
So dvUplink1-3 were configured as active for my LAN facing port groups. VMotion were configured as "not used" for LAN facing port groups.
VMotion were configured as Active for VMotion port group, dvUplink1-3 were configured as "not used" for this portgroup.
Later i decided to increase my number of Uplinks in order to connect yet another VMotion NIC for each host. Of course i could have used dvUplink3. But i wanted to leave that one becasue it will be used for LAN port groups in the future. Afterwards it was really stupid to have dvUplink3 disconnected and marked as active on LAN port groups.
So i added a new dvUplink called VMotion2. Dont recall if i connected it to the vmnics on the host at the same time or not. But i do not think that matters. Becasue this is what happened
dvUplink1 - Connects to LAN NIC with several VLANs
dvUplink2 - Connects to LAN NIC with several VLANs
dvUplink3 - Connects to dedicated vmotion NIC
VMotion - Not connected
VMotion2 - Not connected
So when dvUplink3 got "link up" a lot of my virtual machines were rebalanced on to that uplink. But since it goes to dedicated VMotion VLAN i lost communication with a lot of machines. Of course one of them were vCenter server. But a few CLI lines to unassign the VMotion vmnic from the uplinks solved the issue.
So vCenter/dvSwitch automatically re-ordered my Uplink associations. I was stunned by this. Is this expected behavior or not? If it is i guess i will run my VMotion traffic in a seperate dvSwitch. Or at least make sure i do not have a uplink in the "middle" without a connected vmnic.
If it is expected behaviour. Is it possible to make sure that the order is not changed? I just assumed that the association between Uplink and VMNICs were static. Who knows, would it be possible that certain changes to the dvSwitch/Uplinks will result in automatic re-order so that VMotion uplink goes to a LAN vmnic and dvUplink2 goes to VMotion vmnic?
cheers,