vCenter Migration

azjag

I felt I would post this here to see if anybody else has come across this. Otherwise it is a good way to test your knowledge.

We recently purchased new hardware and installed esxi5 on all of them. Over a period of 3 months we migrated all of our production vm's over to the new environment with the exception of vCenter. In the new environment we are using vDistributed Switches exclusively. In the esxi4.1 environment we only had vStandard Switches. We upgraded the vCenter server to version 5 as well.

The problem we ran into was the single instance of vCenter in our environment on an older version of esxi. vCenter needed to be up to vmotion from one host to another and set the networking configuration. The migration also needed to be done without affecting production i.e. no changes to networking, storage or hosts. My resolution below.



What I came up with,
Power down vCenter and clone it to the new environment. Power up the original and clone(Nic Disabled) and update vmtools. Shutdown clone and configure the nic to use the vDS in the original vCenter. Power down and disable vcenter server in old environment. Power on the clone and test. After 3 hours of work the vCenter instance is up and running on the new servers without affecting production.

If you know of a better way this could have been done or have questions please chime in.

jmritenour

I guess it would depend on how large the environment is, and what kind of DB server being used. When faced with this sort of situation previously, I end up building a new vCenter VM, connecting to the existing database (after the old vCenter was down, obviously), and upgrading the vCenter DB, which was running on a dedicated server.

But I have used a technique similar to yours, for cloning and P2V migrations where I needed to keep the original up and in production while I did some configuration of the new VM

jibbajabba

You already upgraded the vcenter to version 5 so that is good. You can have cluster with mixed versions of vSphere as long as the CPU family is the same so you could have added the 4.x host with the vcenter to a 5.x cluster and migrated the vcenter vm onto a 5.x host.

azjag

jibbajabba wrote: »

You already upgraded the vcenter to version 5 so that is good. You can have cluster with mixed versions of vSphere as long as the CPU family is the same so you could have added the 4.x host with the vcenter to a 5.x cluster and migrated the vcenter vm onto a 5.x host.

Both clusters were managed by the same vCenter server and in order to migrate from 4.x to 5.x we would need to change the nic from vSS to vDS. This is where the problem lies as you can't vMotion without vCenter and once you migrated from 4.x to 5.x vCenter would lose connection.

jibbajabba

Got any spare nics ? You could simply attach the old and new hosts to both, vSS and vDS and change the nic manually of the vcenter. I have done so myself. A customer had a 5 host cluster running 4.x and he needed to be on 5 for licensing purposes - I migrated him to 5.x completely without downtime ..