I have upgraded my VMware host to vSphere 6.0 today.
The upgrade procedure has been smooth as expected and after 10 minutes my host been reachable again.
Though I had to install the new vSphere Client and once successfully connected I had a surprise.
My iSCSI based storage could not be detected by ESXi even the configuration looked correct and the ping tests were successful.
After trying several recovery actions, the one which has been successful for me was to add one new LUN in my iSCSI target.
Once I have added the new LUN to the existing iSCSI target and I have triggered the rescanning, my storage has been revived.
One additional info is that I have Cache SSD hard drives on my iSCSI device (Synology 1813+).
I am not sure this had anything to do with the initial glitch, but I thought is due to “caching” wrong information and when I have added the new LUN, the information has been refreshed in cache.
If you have a similar problem, please post a comment – I am keen to hear about it.