ESXi upgrade scenario

[griese]

We're contemplating killing two birds with one stone in our ESXi upgrade.  Currently we have a 4.0 ESX cluster with a mixture of old and new hardware that is configured as Intel Xeon 45nm Core 2 EVC Mode.  We have some spare capacity and some new hardware that we'd like to replace some of the old hardware with.  Here's what we'd like to do.

1.  Create a new 4.1u1 ESXi cluster with some of the new hardware and set the EVC mode to Intel Xeon Core i7.  CONNECT THIS CLUSTER TO THE SAME DATASTORES AS THE OLD 4.0 ESX CLUSTER.

2.  Migrate VMs from the old 4.0 ESX cluster to the new 4.1u1 ESXi cluster.

3.  As resources are vacated and become available on the old cluster, we would remove hosts from the old cluster, reinstall 4.1u1 ESXi on them, and add them to the new cluster.

To date, we've only had one cluster so I have a few questions.

A.  Does this scenario sound like it will work o.k.?

B.  Is there a problem connecting two separate clusters to the same datastores to facilitate quicker migrations (non-storage vmotions)?  Any conflicts?

C.  Will I be able to do live vmotions between clusters?

Thanks,

Troy

[idle-jam · Accepted solution]

A and B Yes, for C i would a down time as you will need to upgrade vmware tools as well ..

[griese]

Thanks idle-jam.

That's what I thought regarding A and B.  We were planning on upgrading tools after a majority of the VMs have been migrated.  Giving us a backout plan by putting them back on the 4.0 cluster if necessary.  Once we've gotten most of the VMs and a little bit of time on the new cluster we would plan on doing the tools upgrade.

Would it be possible to do a live migration between clusters though?

[idle-jam]

yes it is possible. The important think is to ensure you CPU is compatible or Enhanced VMotion Compatibility enabled

[afertmann]

Troy,

Make sure you upgrade your vCenter to 4.1 first before doing anything,  Then I'd take the new machines and join them into the existing cluster and vMotion the VMs to the new machines.  Then disjoin the old machines and rebuild with ESXi4.1u1.

This is the safest path with no downtime for your VMs aside from when you have to upgrade VMwareTools.  Also if your VMs are still on Virtual Machine v4, upgrade them to v7 before you do the Tools install.

To answer answer your last question.  You cannot live vMotion between clusters.

[EDIT]  This is a stipulation that you CAN vMotion between clusters as long as everything thing between the 2 clusters are the same:

That is:

The 2 clusters can talk to eachother over the service console network / management network.

The 2 clusters are on the same vMotion network (They can VMKPING each other).

The VM PortGroups are the same in the source and destination.

The SAN Volume is mounted in both places.

As all this is possible, I'm not a big fan of that upgrade path as there are a bunch of variables.  What I stated above is pretty safe.

[griese]

Good point on the vCenter.  We'd planned on that, but I neglected to mention it.

According to your suggestion, if I just added the new hosts to my existing cluster then I wouldn't be able to update the EVC mode to i7.  Unless I'm missing something with the newer version.  From what I understood, you could only change EVC when all of the VMs in the cluster are powered down.

Thanks afertmann!

Troy

[JeanFrancoisL]

Are you sure about "upgrade them to v7 before you do the Tools install." ?

Shouldn't it be the reverse ? First upgrade tools, then upgrade HW.

If you first update the hardware to V7, the host may not have the proprer drivers installed...

[afertmann]

You are correct sir. That was a brain fart on my part. Thank you for correcting that.

[Walfordr]

griese wrote:

Good point on the vCenter.  We'd planned on that, but I neglected to mention it.

According to your suggestion, if I just added the new hosts to my existing cluster then I wouldn't be able to update the EVC mode to i7.  Unless I'm missing something with the newer version.  From what I understood, you could only change EVC when all of the VMs in the cluster are powered down.

Thanks afertmann!

Troy

This is correct you can only change EVC with all the VMs off.

To your initial questions:

A. Yes

B. Should not be a problem. You are connecting the Hosts and not the cluster. I have 3.5 and ESX4.1 u1 hosts on the same LUNs.

C. You can vMotion between the clusters if your EVC levels match. In order words old_cluster1 does not have more or less SSE features than new_cluster1.

Also the post above mine is correct. You will need to upgrade VMware tools before the virtual hardware.  If you do not you can loose the network settings on the guest.  If you have VMware Update Manger installed the good news is that there is a pre-build base line that will take care of tools and the vhardware in the correct order.

[sugadada]

That's great info to keep in mind when I upgrade my environmen.

[griese]

UPDATE:  I performed the procedure as I described and all was well.  Two clusters attached to the same storage.  vMotion from old ESX 4.0 cluster to new ESXi 4.1u1 cluster worked just fine even though the EVC modes were different.  Hope that helps.

Troy