Tuesday 21 February 2012

Upgrade to vSphere 5 - Brief checklist

Recently I have completed the upgrade of one small vSphere 4.1 farm to vSphere 5. Quite soon I will need to upgrade another vSphere 4.1 farm with similar specs, so I decided to write down the brief checklist.
This is not a universal upgrade scenario and it is very specific to our hardware and vSphere configuration, which I will provide below, however, this can be a good high level plan which you can adjust to your environment.


Our vSphere enviroment is hosted on 4 HP Proliant BL460c G7 servers in HP BladeSystem C7000 Enclosure. We use HP FlexFabric VirtualConnect modules to connect to SAN and Ethernet switches. The storage space is provided by EVA 6400.


All ESXi hosts had the latest ESXi 4.1 U2 firmware. vCenter is installed on a physical server and was connected to another vCenter server by Linked Mode. There are about 80 VMs, mostly Windows 2003 and 2008 R2.


So, here is very brief plan for vSphere 5 upgrade, no screenshots or monkey-donkey procedures are provided :) 


0. Build Test Lab


If you have spare hardware with similar specs build a test lab to reproduce the current infrastructure. Test and document the upgrade process. 


I spent a week to build identical vSphere farm including couple of virtual MS Failover clusters. This gave me confidence that I can easily failover MS cluster services between nodes running on different ESXi versions.


1. Compatibility List


This was the most difficult and time consuming part of the upgrade. You need to start with VMware Compatibility Guide. It is very extensive. Make sure you have tested every single part of your infrastructure against this HCL, e.g. network driver, HBA firmware, server's BIOS, SAN switch firmware. That will help you to stay on the safe side and be able to get support from VMware in case you face issues with vSphere 5.If you have similar hardware you can find this post useful.


The VMware HCL is not the only place to check. In my case I had to check HP Single Point of Connectivity Knowledge (SPOCK) to verify approved firmware/driver versions for vSphere from the HP standpoint.


You will for sure find some components to be updated and probably you will need to schedule some maintenance time during the weekend. In my case I had to upgrade HP EVA 6400 Firmware to the latest version to meet vSphere 5 prerequisites. 


Once you align your infrastructure with Compatibility List you can proceed with step 2. 


2. Host Agent Pre-Upgrade Checker


Run Host agent pre-upgrade check to make sure the new vCenter agent will be installed sucessfully. 


This is quite simple task that will check if VPX agent can be upgraded successfully. Make sure you run it as administrator otherwise it won't show your system DSN for vCenter database. 

3. Upgrade vCenter

a. Uninstall Linked Mode



vCenter upgrade guide says it will uninstall Linked Mode automatically as versions 4 and 5 are not compatible with regard to Linked Mode. However, I prefer to keep it in a controlled way.

b. Check Database Compatability Level and permissions


You will need to check the following document for specific details on your database type


c. Check vCenter prerequisites


The same document will be useful in this case again.


d. Backup vCenter database. 



Not much to tell about it :)


e. Run vCenter Installation Wizard


All you will need here is clicking Next and credentials for vCenter Database.

4. Upgrade vSphere Update Manager


In my situation VUM was not really useful. First, I planned to use for the hosts' upgrade, but it failed twice. Therefore, I left this as a last task.

5. Upgrade Hosts

a. Put the host in Maintenance mode.



b. Disconnect all LUNs 


You can unplug FC cable, unpresent LUNs, disable ports on SAN switch. With HP Virtual Connect I simply unassigned FC SAN from server's profile.

c. Be careful by choosing the right ESXi image for upgrade



If you installed previous version of ESXi with HP customized image be sure to use HP ESXi 5.0 image for upgrade. You can download it here
I didn't pay attention to this fact so my first attempt of upgrade with VUM failed - newly upgraded host couldn't be added to vCenter. This particular issue is explained in HP Support Document.

d. Consider upgrading directly from ESXi ISO



Second attempt of host's upgrade with VUM failed as well. The installation process stuck at “About to install” stage. Seems like HP ESXi  5 ISO doesn't support upgrade with  VUM. If you don't have big number of hosts it is not a big deal.

e. Reconnect Host



Once the host is upgraded you need to add it to vCenter and get SAN connectivity back.

d. MS Failover Cluster pRDM disks



If you have virtual MS Failover Cluster nodes in you vSphere you will need to run the following command in order to fix the long boot time issue.
esxcli storage core device setconfig -d device .naa --perennially-reserved=true for each LUNs presented to virtual

Here you can find additional details.

6. Upgrade/Migrate to VMFS-5



You very probably read about VMFS-5 and difference between new and upgrade VMFS-5 datastores. For me the biggest driving force to go with new VMFS-5 datastores was the fact that block size was different across old datastores. That was causing slow Storage vMotion. Duncan Epping gave very nice explanation of the nature of this problem. 
If you don't spend days and weeks (depends on the number of your datastores and your storage performance) moving your VMs around you'd better have very clear understanding about your final Datastore design. Considering new features like Storage DRS and Profile-Driven Storage this can take you quite some time.

7. Updating VMware tools.



Depending on how critical your VMs and their services are you can go either with VUM VMware tools upgrade or manual upgrade.

8. Upgrade VM hardware



The same story here. We don't have hundreds and thousands of VMs, therefore, I preferred to upgrade virtual hardware manually. This gives me  feeling of control :) if your VMs have Hardware Version 7 you can take advantage of VM snapshots to be able to revert Virtual Hardware upgrade. 




Sure, this checklist is not even close to the proper upgrade procedure, but this might be a good starting point for your own upgrade plan.




Feel free to give me your feedback. Really appreciate it.


Update 1


Do not forget to upgrade youк dvSwitch to version 5 as I did. It has to be done once your vCenter and ESXi hosts are upgraded.


If you find this post useful please share it with any of the buttons below. 

1 comment: