Yesterday at the Dutch VMUG I was talking to my friend @GabVirtualWorld. Gabe mentioned that he had just upgraded his vCenter Server to 6.0 U2 in his VSAN environment, but hadn’t upgraded the hosts yet. Funny enough later someone else mentioned the same scenario and both of them noticed that the VSAN Health Checks were disabled after upgrading vCenter Server. Below a screenshot of the issue Gabe saw in his environment. (Thanks Gabe)
So does that mean there is no backwards compatibility for the Healthcheck, well yes and no. In this release we made our APIs public, William Lam wrote a couple of great articles on this, and in order to deliver a high quality SDK backwards compatibility had to be broken with this release. So if you received the “health checks disabled” message after upgrading to vCenter Server 6.0 U2, you can simply solve this by also upgrading the hosts to ESXi 6.0 U2. I hope this helps.
** Update March 23rd **
Please note that ESXi 6.0 Update 2 is also a requirement in order to enable the “Performance Service” which was newly introduced in Virtual SAN 6.2. Although the Performance Service capability is exposed in vCenter Server 6.0 Update 2, without ESXi 6.0 U2 you will not be able to enable it. When trying to enable it on any version of ESXi lower than 6.0 U2 the following error will be thrown:
Status: General Virtual SAN error.
Start Time: Mar 23, 2016 10:55:35 AM
Completed Time: Mar 23, 2016 10:55:38 AM
Error Stack: The performance service on host is not accessible. The host may be unreachable, or the host version may not be supported
This is what the error looks like in the UI: