relationship between clusters and host groups
Due to circumstances beyond my control, over time and several upgrades of vSphere, there is no longer any commonality between the clusters in vSphere and what I see as host groups in the FlashArrays....
Forum Discussion
david_schramm​, There are a couple parts that I'd look through to see what kind of drift you have here. Is it just drift or outdated information at the host name and host group level?
General best practice would be that each ESXi initiator would map directly to a single FlashArray host object. Then each ESXi cluster would map directly to a single FlashArray host group object. Ideally the name of the ESXi cluster would be the name of the FA host group, and the hostname of the ESXi host would be the name of the FA host, but names can change and it's usually not too big of an issue.
Or is the issue that ESXi inits have moved in and out of ESXi clusters or between vCenters? In which case the hosts on the array were not moved out of one host group and added to another host group? And now you have hosts in the wrong host groups and unable to mount to the VMFS datastores?
The other more complicated drift issue is if the host ports on the FA host object are not correct. This can happen if FC cards are changed or moved between hosts, for iscsi if re-imaging happens or host names change. Or it can happen where you have host ports from several ESXi inits added all to a single FlashArray host object?
But if it's esxi name to host name drift, the objects can be renamed fairly easily. If it's an issue with ESXi hosts being in the wrong host groups, then it's a little tricky to fix, but is generally safe to move hosts to the correct host groups by putting the hosts into maintenance mode, sometimes unmounting them from the current datastores on those arrays, and then moving them to the correct host groups and remounting them.
