Even if you are not using VMware Update Manager, a typical patch workflow may look something like this:

1. Take VM snapshot
2. Apply updates, which normally require that you…
3. Reboot
4. Test
5. Remove snapshot

After I wrote yesterday’s post on Hyper-V snapshots, something occurred to me.  The 5 steps above are only for VMware ESX.  If you are using Hyper-V as your platform, you are not done yet — the snapshot differences are not actually merged until the VM is powered off.

Hyper-V administrators, please add the following steps:

6. Power off VM
7. Wait for merge to finish
8. Power on VM

Patch Tuesday. Would you like one reboot or two?

Related posts:

1. IGT Part 5: Hyper-V snapshots are not gone until the VM is powered off
2. Hyper-V snapshots: not for production
3. Snapshots that shoot back
4. VMware vSphere 4 has a Snapshot Alarm

Here is the document intro:

VMware Update Manager (VUM) provides a patch management framework for VMware Virtual Infrastructure. IT administrators can use it to patch VMware ESX, Windows, and certain versions of Linux virtual machines.  As data centers get bigger, performance implications become more important for patch management. This study covers the following topics:

• Benchmarking Methodology
• VUM Server Host Deployment
• Latency Overview
• Resource Consumption Matrix
• Guest Operating System Tuning
• Network Latencies
• On-Access Virus Scanning

Download it if you want to learn more.

Related posts:

1. vSphere Thin-Provisioned Disk Performance
2. Half the VM reboots on Patch Tuesday
3. Don’t know much about resource pools
4. Awesome performance through VMware DRS