Since vSphere 6.7 U2 SMB protocol was introduced to allow you to backup to a file share. This was excellent news for us and I decided to test it and see how it works. Upon setting up the backup schedule I got this errorSo I attempted to use the option to do a one off "Backup" and you get this message instead
Both messages didn't really point me to any particular direction so I did a quick search on VMwares knowledge base and found an article KB70646 which states that it is only supported for SMB1 and currently it is still not fixed in U3 (Tested on Build number 15132721) either. We all know SMB1 is insecure and shouldn't be using it but I still wanted to try and see how it worked so first I enabled SMB 1 on my server. For reference of the powershell cmdlets to run go to this Microsoft article which covers SMB1/2 and 3.
Once I had SMB 1 enabled I attempted to set the backup schedule and as I was filling in the "Backup server credentials" section I was expecting to include my domain name such "myvmx\yungk" or "[email protected]" for the "user name" as the share I created was using AD permissions to control access. Using either of the format was giving me the same error messages as above and it appears that the only way it worked was to just use the account name i.e "yungk" which work immediately.
It's not ideal to use SMB to do your VCSA backup yet unless you are willing to use SMB 1 protocol which I am pretty sure you would have your security team knocking on your door tell you to not use it.