After the update 2 fiasco, update issues still exist with VMware ESX and ESXi. When the VMware Update Manager scans a host for updates, it may show no updates, updates that you think have already been applied, or out of sync updates.
One source of confusion: when a system is installed with Update 2, Update 1 is seen as an update to the system as well as Update 2.
Another source of confusion: the Time bomb fix may not appear appropriately or appearing after the system was updated using the latest ISO.
We depend on VMware Update Manager (VUM) to tell us when we need to do updates. So this should be as accurate as possible. Apparently the problem is not with VUM per se, but with the database being out of sync with the VMware ESX or ESXi host.
If you did not use VUM to do the update, then it is confused about the system, and a scan will show issues. Once you remediate the updates, nothing is done on the system, but now VUM is not longer confused. This is something of a split-brained behavior easily corrected.
Update 2 also added in a very important new feature that may cause confusion as well: Enhanced vMotion Capability (EVC). Setting up EVC takes quite a bit of work and only benefits the most recent systems.
EVC support required me to shutdown all my VMs, change 2 BIOS settings on ALL my VMware Cluster nodes, reboot them, and start my VMs. I could not do this while the VMs were running.
EVC will not be beneficial until you bring in the next generation of systems and processors into your VMware Clusters, but will you have to bring down all the VMs within all nodes to enable EVC on a new node. This will be an issue going forward.
Virtualization expert Edward L. Haletky is the author of "VMWare ESX Server in the Enterprise: Planning and Securing Virtualization Servers," Pearson Education (2008.) He recently left Hewlett-Packard, where he worked in the Virtualization, Linux, and High-Performance Technical Computing teams. Haletky owns AstroArch Consulting, providing virtualization, security, and network consulting and development. Haletky is also a champion and moderator for the VMware discussion forums, providing answers to security and configuration questions.