Is common VLAN among all hosts in a cluster a pre-requisite for DRS & HA ?

[Sam30]

I believe common VLAN among all hosts in cluster is a pre-requisite for DRS but not for HA?

Scenario:-

I've 4 hosts in a DRS enabled cluster with shared storage but all of them don't have all the VLAN's :-

Host1 - VLAN1 & 2

Host2 - VLAN1 & 2

Host3 - VLAN1,2,3 & 4

Host4 - VLAN1,2,3 & 4

Question 1

I believe common VLAN is a pre-requisite for DRS?

The VM's connected to VLAN 3 & 4 will always be moved only between Host 3 & Host 4 by DRS. Correct?

DRS will never move the VM's connected to VLAN 3 & VLAN 4 to Host 1 & Host 2 as those VLAN's are not there on Host 1 & 2?

Question 2

I don't believe common VLAN is a pre-requisite for HA?

How about HA? In case of Host 3 failure will the VM's with VLAN 3 & 4 be restarted only on Host 4 or they'll be restarted on any of the Hosts irrespective whether the VLAN 3 & 4 are available on other hosts or not?

[rcporto]

HA and DRS don't look for VLANs configured in hosts... they will look for Port Groups when migrating or restarting a VM... but even with all Port Groups created on all hosts, if one of Port Group have a mismatch VLAN, the DRS/HA will migrate/restart the VM but this VM will be isolated, since the VLAN of Port Group is incorrect.

To minimize this, if you're unable to create Prot Group/VLANs in all hosts, you can create Host Affinity Rules to prevent a VM be migrated to a host that not have the appropriate VLAN.

[Sam30]

So you are telling me that even if Hosts 1& 2 don't have portgroups for VLAN 3 & VLAN 4.

VM's on Host 3 & Host 4 connected to portgroups VLAN3 & VLAN4 will still be automatically migrated to Host 1 & Host 2 via DRS even though they don't have that port groups?

[rcporto]

VM's on Host 3 & Host 4 connected to portgroups VLAN3 & VLAN4 will still be automatically migrated to Host 1 & Host 2 via DRS even though they don't have that port groups?

No, to migrate the destination host must have the same port group, but the port group can be on different VLAN and DRS will not look to this.

[Sam30]

Yeah so when I say VLAN 3 & VLAN 4 I'm referring them as portgroup label on each host.

So the VM's which are connected to portgroups with network label VLAN 3 & VLAN 4 will not be moved automatically by DRS to Host 1 & 2 as they don't have the port groups with network label VLAN 3 & VLAN 4. Correct?

How about HA, if the Host 3 fails ?

Will the VM's on Host 3 which are connected to portgroups with network label VLAN 3 & VLAN 4 be restarted by HA on Host 1 & Host 2 even though they don't have the port groups with network label VLAN 3 & VLAN 4 or they'll only be restarted on Host 4 as it's the only host left which has network portgroups with VLAN 3 & VLAN 4 ?