rm_bk
Enthusiast
Enthusiast

Clusters with mixed ESXi versions: "officially supported" vs "discouraged?"

  • Some people say it's fine, period.
  • Some people say it's fine only in the short term (i.e during rolling upgrades).
  • Some people say it's strongly discouraged and you really shouldn't do it at all.

What's the official word from VMware on this?  If we have a problem and we open a support case, will we be advised to move away from this setup?  Have they published any guidance here?

What's the real world experience?  Has anyone had a support case that could be definitively blamed on their mixed version clusters?

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daphnissov
Immortal
Immortal

Some people say it's fine, period.

I know of no one who would say categorically that "it's fine" without some caveats.

I don't know what the "official" support stance is from VMware, but I will give you some real-world advice and also a personal recommendation.

Mixing builds within the same release is mostly ok with there being some serious caveats:

  • feature sets change
  • security implications may differ
  • advanced settings are shifted with some introduced

Mixed clusters across different releases (i.e., a cluster containing 6.0 and 6.5 hosts) is a mistake and should absolutely be avoided. Caveats are as above but more severe.

My personal recommendation:  Always, always strive to keep build numbers consistent within a cluster unless you have an extremely compelling reason. Laziness or not wanting to update your clusters is not a good reason, btw. Clusters across releases should be strictly avoided.

So what you need to ask yourself is this:  Why am I wanting to have a heterogeneous cluster? You need a very good reason.