I usually check whether the password have expired (or simply set them) for root and administrator@vsphere local, and also run nslookup <IP-address> to verify proper DNS reverse resolution. If the integrated checks then don't show any more issues, you should be fine.
If the upgrade fails, it's usually in a state where you can easily revert to the old one. However, if it fails at a late state there might be some things to consider if you want to revert to the old one, e.g. Domain membership, HA-Agents on the hosts, ...
Anyway, with the major checks done, the upgrade should work as expected.
The above assumes that you are upgrading from a supported 6.5 build. Not all of them may be supported (note the small "!" icon in the interoperabiliy matrix)!
Logged in to VCSA with administrator account and logged to VAMI with root account. Both worked fine so password should not be expired.
From which machine should I test nslookup and should I test again the current VCSA ip or the new (temporary one)?
Entering just nslookup on the current VCSA shows:
Confirmed it can resolve the hosts FQDN
Pretty sure it was pointed to the DNS Server so not sure why seeing 127.0.0.1
Yes upgrade supported as 6.7U2 came after the 6.5U2 version I have installed.
information only says: For vCenter Server 6.7.0 onwards, applies to vCenter Server as well to Update Manager.....thanks for highlighting this.
Ok, go for it ;-)
Btw. assuming that you've properly configured the DNS server address(es) on the vCSA, nslookup <IP-address> can be run from e.g. your PC/Server. It's only to ensure that the IP address will be resolved to the host name (reverse DNS).
Will do, also out of curiosity does it matter at all if I have some hosts still going into maintenance mode whilst I upgrade or already in Maintenance mode?
I'd try to keep changes at a minimum while upgrading vCSA. However, unless the host on which the vCSA runs, and/or is deployed stay are not going into Maintenance Mode, it should be ok. Please note, that you should set DRS to "Manual" during the upgrade to avoid initial placement, or movement issues with the vCSA.