DRS: VM migrate without reason

[JonSnow_Stark]

Hello all,

I'va a serius problem with my VI3.

I've 6 HOST (ESX3.5U1) with HA/DRS (fully automated : moderate)

- 3 Host in a datacenter "Room A" and three HOST in another datacenter "Room B".

The three HOST in Room A have a specialized port group on a vSwitch named "VLAN-Room-A".

Curiously, sometime, a VM attached on the port group "VLAN-Room-A" migrate on a ESX in the "Room B".

The VM boot but without network of course.

I cannot understand this behavior ?

Could you help me please.

Thanks in advance.

[mikepodoherty · Accepted solution]

Are all 6 hosts in the same HA/DR cluster? If so, recreate the clusters as separate for each room. Otherwise, DRS will migrate to the host that best supports the additional load and it does not check for VLANS.

[JonSnow_Stark]

How !

Yes, All hosts belong to the same cluster ha/drs. but the port group name "VLAN-Room-A" is only defined on host in "room A"

I'm very surprise DRS not be able to check the existence of the port group and the datastore before migrating a VM.

Thanks for the answer.

[mikepodoherty]

You should be set up so that VMotion is on a separate network from the port group for the guest server communications, the migration takes place on the VMotion VLAN (network communications) not on the VLAN supporting the guest servers. That is how it happens.