Migrate Virtual Machines (VMs) and VMkernel Adapters from Distributed Switch (vDS) to Standard Switch (vSS)

Products

VMware VMware vCenter Server VMware vSphere ESXi

Issue/Introduction

Migrate networking from a Virtual Distributed Switch (vDS) to a Virtual Standard Switch (vSS).
There are many caveats to this process that can make it more complicated and change the steps involved. If there are any relevant configurations that will be impacted by the change, for instance iSCSI port binding on the vmkernel adapters being migrated or moving uplinks that are in a LAG on the vDS, check with your network team or open a case with Broadcom Global Support to assist in the change.
Before proceeding, ensure out-of-band access to the host if possible, in case management connectivity is lost.
Perform these changes in a maintenance windows if possible, as this can potentially cause loss of network connectivity for the host or VMs.
Additionally, it would likely be helpful to record the following before proceeding:
- All vmnic-to-dVuplink mappings on the host. For example, if dVuplink1 maps to vmnic2 on host1, it should be reconfigured as such if adding the host back to the same vDS.
- All vDS portgroups settings/policies in vCenter, including VLAN tagging or security settings, will need to be replicated on the vSS.
- All VMs portgroup assignment per virtual adapter, for example Virtual Adapter 1 connects to portgroup A but Virtual Adapter 2 on the same Virtual Machine connects to portgroup B.

Environment

VMware vSphere

Resolution

Migrate VMs and VMkernel adapters from distributed switch to standard switch:

Create a standard switch (vSS), and in the wizard do not check options to add vmkernel adapters or vmnics; only add a Virtual Machine (VM) portgroup to start.
- For guidance, see: Create a vSphere Standard Switch
On the vSS, add the VM portgroups that exactly match the settings of the VM portgroups on the vDS, VLAN, Security settings, etc..
From the host view in vCenter, navigate to Configure -> Virtual Switches and select “Manage Physical Adapters” for the vDS and remove one vmnic from the dVuplinks.
Note: This may result in some brief packet loss, typically equivalent to one ping, to anything using the NIC being lost as it fails over. As long as the remaining uplink has the same connectivity/configuration to the physical network, host and VMs should maintain overall connectivity.
Add the removed vmnic to the vSS as an uplink.
Migrate the management vmkernel adapter from the vDS to vSS; click the ellipses next to the standard switch on the host we are migrating to and select “Migrate vmkernel adapters”.
Note: This may result in some brief packet loss, typically equivalent to one ping, to the vmkernel adapter as it migrates over. As long as the remaining uplink has the same connectivity/configuration to the physical network, host and VMs will maintain connectivity.
Repeat step 5 for any remaining vmkernel adapters from the vDS to vSS.
Change VMs to use portgroups on the vSS:
1. In the VM settings, change the network label to the appropriate portgroup on the vSS for each Network Adapter on the VM.
2. VM typically only lose one ping.
3. Perform the same steps on all VMs, including powered-off VMs and templates.
Once all VMs and VMKs are off the vDS, remove the remaining vmnic uplink(s) from the vDS, and add to the vSS following step 3 and 4 above.

Migrating back to a distributed switch:

You can migrate back to a vDS using one of these options:

Migrate all host networking to the vDS at once:
1. Right-click the vDS in vCenter and select "Add Hosts" if the host has not been added yet or was previously removed, or "Manage Hosts" if it is currently added to the vDS.
2. Select the host to add/manage, and the physical adapters(vmnics) to use/add to that vDS.
3. Select any vmkernel adapters to migrate, and choose the portgroup on the vDS to migrate them to.
4. Select to migrate VM networking, and for each VM, select the portgroup on the vDS to migrate to.

NOTE: If all vmnics are being removed from the vDS in the above step, ensure all vmkernel adapters and VMs are also being moved over as well or they will remain on a switch with no uplinks and therefore no connectivity.

Migrate networking to the vDS over several steps:

NOTE: If migrating the management adapter from a vSS to vDS, this may be a safer option to avoid or reduce the risk of losing management to the host should any issues arise during migration. Generally, management is recommended to remain on a standard switch for recovery purposes unless the design requires otherwise.

If the host has not been added yet or was previously removed, right-click the vDS in vCenter and select "Add Hosts" and select the host you want to manage, then complete the wizard without selecting/migrating any vmnics, vmkernel adapters, or VMs; this step is only to add the host to the vDS.
From the host view in vCenter, navigate to Configure -> Virtual Switches and select “Manage Physical Adapters” for the vSS and remove one vmnic and add it to the vDS using "Manage Physical Adapters" next to the vDS you are migrating to. Note that there should be at least one vmnic still on the vSS capable of passing the traffic.
On the same page, click the vertical ellipses next to the vDS and select "Manage Networking" and complete the wizard with only migrating the management vmkernel adapter from the vSS to vDS.
Repeat step 3 above as needed for any remaining vmkernel adapters and VMs (note that each interface on the VM needs to be assigned to a network on the vDS).
Once the standard switch has no remaining VMs or vmkernel adapters, repeat step 2 to move the remaining NICs to the vDS.

Additional Information

WARNING: Please note that moving uplinks between vDS can result in loss of connectivity to the host or its VMs. If you experience any issues with connectivity during the migration, please contact support for additional assistance.