ESXi host and VM hardware upgrades

[steve_au]

Hi all,

I pretty much know the answer to these questions (I'm reading the manuals), but just wanted some re-assurance from those who have ventured on before me.

1/ when upgrading ESXi hosts from 3.5 to 4.0, it's my understanding that there's no real urgency in upgrading the guest VM's (Tools and hardware to version 7) because vSphere 4.0 will happily run with the older VM's (albeit without the new features). However, I'm just wondering if anyone has experienced any issues by not upgrading the VM's soon after the host upgrade. My intention is to do it very soon after, but sometimes best laid plans go out the window in my role,so I'd feel comfortable if I new I could run the older VM's indefinitely without any problems.

2/ how "safe" is upgrading the VM hardware version from 4 to 7? Being VMware I don't expect any issues, but I'd like to know if anyone has experienced any issues that may cause extended downtime for the guest VM.

Thanks in advance,

Steve.

[a_p_ · Accepted solution]

1. I would separate between VMware tools and the hardware upgrade. The new tools not only update virtual hardware drivers, they also update ballooning and other features VMware uses to communicate with the guest OS. In my opinion you should upgrade VMware tools as soon as possible. I can't tell for sure if you will have any issues without upgrading. My personal opinion/experience is, that during "normal" operations the old tools will do.

The hardware upgrade should not matter too much. In large environments with hundreds of hosts, you will actually need to update all hosts (in a cluster) before upgrading the hardware in order to not loose the ability to vMotion guests to 3.5 hosts.

2.The only issues I had so far with upgrading the hardware were in networking. On a few VMs I had to manually reconfigure networking after the upgrade.

André

[steve_au]

Thanks for the input. I'm confident it will all go well.

[LucasAlbers]

I think i remember windows wanting to reactivate after I upgraded.

In addition I remember something about disks being seen as external storage and getting disconnected on upgrades.

It makes sense to split your upgrade into discrete steps to improve troubleshooting.