There is a new version for the monitoring plugin check_esxi_hardware available!
Today's release (version 20150109) allows handling of multiple serial numbers. This makes particularily sense when a Blade Server is checked, because in many cases the serial number of the chassis AND of the blade server is returned.
The new output will now look like this:
OK - Server: Cisco Systems Inc R210-2121605W s/n: XXXXXXXX Chassis S/N: XXXXXXXX System BIOS: C188.8.131.52h.0.071820120442 2012-07-18
The relevant code modification was already done several months ago, but I only merged to the master tree today. I'm sorry for the delay.
Big thanks to Helmut Eckstein and Andreas Daubner for testing the new version.