Demystifying The ESXi Upgrade Process

A common question which gets asked allot is; Should I upgrade my ESXi hosts or do a fresh install ?

Most people when asked that question would be inclined to say “Fresh Install” when challenged some of the excuses I hear are ” It will carry over a load of crap from the previous release”. This seems to be a mindset we have gotten ourselves in from managing other vendor OS’s (not pointing the finger).

In fact if we were to look at the process in a bit more detail, an upgraded ESXi host is almost identical to a freshly installed ESXi host as..

  • Boot disk is not repartitioned
  • Overwrites boot bank contents
  • Configuration and VMFS volume preserved

Upgrade Process Walkthrough

Step 1: Save the config (state.tgz)

Step 2: Replace VIBs (overwrite)

Step 3: Reboot

Step 4: Config re-applied on reboot


Note. The partition layout is the same now for 6 as it was for 5.x


Don’t be afraid to upgrade!