I was just about to start our upgrade to all things VMware 6.0 (vSphere, hosts, vSAN, etc...), I ran accidentally across this:
If you are running ESXi 5.5 EP06 (Build 2456374) or ESXi 5.5 P04 (Build 2403361) make sure you at least install the updates referenced in the KB, if not get all updates via update manager. Thank you, Zach.
Maybe it's a better idea not to upgrade at all:
ID: ESXi550-201505101-BN
Impact: Critical
Release date: 2015-05-05
Summary: VMware advises not to upgrade to ESX 5.5 Patch Release ESXi550-201504002 released on 4/30/2015. Refer to KB#2116370 for details.
Description: VMware advises not to upgrade to ESX 5.5 Patch Release ESXi550-201504002 released on 4/30/2015. Refer to KB#2116370 for details.
At least wait a few weeks till the problems get solved.
For me it would depend on where vSAN was in use. In our case it's a DR replication target so it's OK to be a bit more aggressive with the upgrade. Any sort of production? Yes, I would wait a bit. Thank you, Zach.
Further discussion with a co-worker = Perhaps you should only install the patch needed to address the vSAN issue. Thank you, Zach.