Upgrading All vSphere Host Server Hardware

[emorgoch]

Hi guys,

Over the next month, we'll be purchasing a series of new servers to replace our current, aging, host servers. Our current servers are as follows:

- 2 x HP ProLiant DL380 G5 w/ 2 x Intel Xeon 5160

- 2 x HP ProLiant DL380 G5 w/ 2 x Intel Xeon X5355

- 1 x Dell PowerEdge 2950 w/ 2 x Intel Xeon 5150

All the servers are running ESX 4.1, with vCetner 4.1 backing them.

The plan is to replace these with 4 or 5 servers running dual Intel Xeon X56xx (probably X5650 or X5680) CPUs. Probably either HP DL380 G7s, or possibly Cisco UCS C210 M2 systems.

Originally, I was thinking that I'd use maintenance mode and VMotion to most the VMs off each host one at a time, and replace it with the new one, etc.

Thinking about it now, however, I'm worried that I won't be able to vMotion from the old servers to the new ones in the end, given the generation differences in the CPUs. Because the CPUs were all the same generation, we haven't turned on EVC. I know this used to require that all VMs in the cluster be turned off before it could be done, but that does not appear to be the case anymore (confirm?).

We were hoping to perform this upgrade without any downtime to the VMs in our cluster, but if it can't be avoided, we'll plan for and work around it. Also, it would be nice to take advantage of the new capabilities/instruction sets on these next gen CPUs.

I've tried finding some guidance within the VMware docs on this, but haven't come across anything yet.

Anyone have some guidance that they can point me to?

[Exwork]

You can enable EVC on a cluster without shutting down the guest, unlike in the past.
You'll need to set your EVC mode to one that will support your oldest servers, your 5100 series boxes - in this case, I believe the 'Intel Xeon Core2' mode.

Once you do that, you can add the new hosts to the cluster, and EVC will mask the feature sets on your new servers to the lowest-common level.

To verify you can use EVC this way, edit your cluster, select EVC, then hit change, and select the Core2 mode. You don't need to hit 'OK' yet. If the compatability window at the bottom says everything is ok, you should be good to enable EVC.

If you get an error at the bottom, then you will have to look a little further.

Later on, assuming you've swapped all your hosts, you can raise the cluster EVC level, and take advantage of the additional feature sets.

If you've got enough spare host capacity, consider pulling one of your current hosts out of your cluster, and make a new test cluster. Create some test guest VMs, enable EVC to support the old host, then add a new host to the test cluster. You should be able to vMotion the guest to the new host, remove the old host, and raise the cluster EVC level. If all is well, dump the test guest, then put your old host back into your main cluster. You should be good for your future upgrade plans.

[emorgoch]

Thanks Exwork.

I'll use this to plan out the upgrade, and will let you know how it all goes.

Evan