Upgrading from 4.0U2 to 4.1U1 and Sharing VMFS Stores Between vCenters

[mlschlot]

We currently have a 5 cluster configuration (1 vSphere, 4 View), four of which are running 4.0U2 managed by a long-in-the-tooth Windows 2003 physical server, 32 bit Virtual Center (4.0.0 - 258672).  The fifth View cluster is running 4.1U1 managed by a new Windows 2008 physical server, 64 bit with Virtual Center 4.1.  Sorry, we just don't feel the virtual centers should be VMs.  Hope that doesn't make me a heretic.

On a cluster basis, my plan is to shut down the VMs on the cluster, disconnect the ESX 4.0 servers from the vCenter 4.0 server, then add them with their associated licenses to the vCenter 4.1 server for management.  Now to the point.  Currently, our ESX 4.0 clusters all share a common set of VMFS storage LUNs, running on an IBM DS4800 SAN. Ultimately we plan to migrate these stores to our new SAN and install ESXi 4.1U1 on new boot volumes.

My immediate concern is if there is anything to worry about after reconnecting a cluster's ESX 4.0 servers to the 4.1 vCenter server and having 2 Virtual Centers (a 4.0 and 4.1 server) managing these multi-cluster shared VMFS store volumes?

[Anfernee86]

If I am understanding your concerns, you shouldn't have any issues as the datastores are managed at the host level, not really at the vCenter level.  You can have different hosts being managed by multiple vCenter servers seeing the same shared storage with no issues.

[mlschlot]

So I shouldn't be concerned about possibly out of sync entries to the vCenter databases?

[Anfernee86]

Nope.  vCenter is going to manage the hosts assigned to it.  The back end storage can be shared by many hosts regardless of vCenter it is assigned to and nothing will be affected in the database.

[AndreTheGiant]

The datastores are not configured and managed by vCenter, but by the host.

So if the hosts can see all the datastores, that's fine.

You can reconnect them to the new vCenter Server.

Andre