Different update levels in 3.5 cluster?

[GlennG201110141]

Is is o.k. to have different ESX 3.5 update levels on different hosts in an HA/DRS cluster?  For example, we have a cluster that includes two ESX 3.5 servers and we want to add an ESX 3.5 U5 server.  Thanks.   -Glenn.

[RvdNieuwendijk · Accepted solution]

Hi Glenn,

welcome to the VMware Communities.

Although I would prefer to have all the cluster members running the same ESX version there is no rule that says you need to have all the ESX hosts running the same version. You can even have a cluster running ESX 3.5 and ESX 4 hosts at the same time. For this latest option you need a vSphere vCenter Server.

Regards, Robert

[MauroBonder]

The recommendation is Maintain similar version of ESX/ESXi within a cluster.
- justification: Having consistent and uniform versions or version families of ESX/ESXi within a cluster allows for easier management and helps make troubleshooting easier by minimizing the number of variables. Maintaining compatible family version of ESX/ESXi within a cluster allows use of features like VMotion, DRS, and FT. FT requires that the hosts have the same version, build and patch level.

Have a cluster with all hosts in same version is  a best practices too.