In VMware KB Upgrading vCenter Server Appliance 5.0.x/5.1 to 5.5 (2058441) the procedure for upgrading an existing 5.0/5.1 vSphere vCenter Server Appliance is outlined, walking you through the steps required including deploying a new 5.5 vCSA and transferring the data from the old instance to the new one. Straight forward procedure, but there is one small caveat in this process.
One important thing to remember, and something I don´t feel that the knowledge-base article highlights well enough is that the new v5.5 appliance should not be configured in any way when deployed.
In my opinion there should be a new step between steps 1 and 2 in the KB article, detailing that the default blank values should not be changed at all.
When using the “Deploy OVF” wizard in the Web Client or Desktop Client, you get asked for network details like IP, subnet, gateway and hostname. In order for the new appliance to successfully import your old data, and take over the old appliance details like hostname, IP adress and so forth, all these values should be left blank while importing to ensure a successful upgrade.
If you do this, the upgrade succeeds as anticipated, and the old vCenter Server Appliance is powered down and the new one takes over.
One of the new features in vSphere 5.5 is the vSphere vFlash that enables you to use a SSD/Flash device as a read cache for your storage. Duncan Epping has a series of posts on vSphere Flash Cache that is well worth a read.
vSphere vFlash caches your read IOs, but at the same time you can use it as a swap device if you run into memory contention issues. The vSphere vFlash Host Cache is similar to the older Host Cache feature, but if you are upgrading from an older version of ESXi there is a couple of things that needs to be done to be able to use this feature.
If you had the “old” Host Cache enabled before upgrading to v5.5, you have to delete the dedicated Host Cache datastore and re-create a new vSphere vFlash resource to be able to use both vFlash Host Cache and vSphere Flash Read Cache on the same SSD/Flash device.
Also note that vFlash Read Cache is only available for VMs that run in ESXi 5.5 Compatibility Mode aka Virtual Hardware Version 10, and is enabled pr. VMDK in the VMs settings.
Now you can utilize vFlash to both accelerate your read IOs, and speed up your host if you run into swapping issues. Good deal!
While deploying a fresh vCenter Server 5.5 Appliance, I ran into an issue getting it configured.
When the appliance is deployed, the first time you log in you get presented with the configuration wizard. The wizard clearly states that if you want to set a static ip, or hostname, you should cancel the wizard, do the network configuration and then re-run the wizard after the fact.
Well, that´s what I did, and it resulted in the following error when trying to create the embedded database:
VC_CFG_RESULT=410(Error: VPXD must be stopped to perform this operation.)
I even tried redeploying the appliance from scratch, but sadly that had the same outcome.
In the end, I was able to complete the configuration by opening an SSH session to the vCenter appliance, and running the following command to stop the vmware-vpxd service mentioned in the error message:
~ # service vmware-vpxd stop
After that I could successfully complete the Setup Wizard. Hopefully this will help someone finding themselves in the same conundrum in the future.
Since my setup is a single host, and at the moment of deploying the vCenter Server Appliance there was no existing vCenter in place, I deployed the appliance directly to an ESXi host. When you do this, you do not get the OVF deployment wizard that asks your IP adresses, netmasks etc. I suspect that this is the root cause of this issue, and that this is something you can/will run into of you deploy it in this manner.