Are there two usernames for virtual machine?

[HelloUbuntu]

I have a windows 10 host and Ubuntu guest. Whenever I start virtual machine I have to enter password for my username, for example "User". But when I try to execute something from my host command line: vboxmanage guestcontrol "My VM" run --username user --password xxxxx --exe "/bin/ls", I have to use lowercase "user" as my username, not uppercase "User", otherwise I get a error: The specified user was not able to logon. I opened the file in guest system, it seems my username is "user". So why is that?

[scottgus1]

There should not be any special setting causing one capitalization of the username to work differently than another intentionally caused through the 'vboxmanage guestcontrol' command.

I tried guestcontrol but couldn't make it work on a Linux guest. But on an XP guest with user 'SnC' I got SnC, snc, and SNC to work. Unless there's a bit flipped in your local setup I'd say there is no case imposed by Virtualbox.

Maybe your guest is case-sensitive?

[fth0]

Like in most OSs, a Linux user has a username and a full name. GUI login screens often allow you to use the full name instead of the username. CLI logins require the username most of the time.