Restore user account from ssh

It's an odd situation.  When you deleted the accounts, the home folders and password entries should have been deleted.  And you say you can log into Frontview with those accounts, or was that a typo?  I suppose that could be because Frontview only checks the passwd file for log-in.

What happens if you try to re-create the user using the same UID as shown in passwd?

I did a quick look in /etc and /frontview and the only places other than etc/passwd, etc/shadow, and their backups (-passwd & -shadow) I can find my user name is ./etc/frontview/user_hf_settings.conf.  passwd and shadow are standard Linux files and contain lots of user names, so obviously aren't where Frontview gets the name list for user management.  user_hf_settings.conf contains only the users added from Frontview (and not admin, either), and it contains information that only Frontview needs to know (snapshot protection, snapshot access).  So,I thought maybe that's where Frontview gets that list, but that din't seem to work out with a couple of quick experiments I ran.

Before you go any further, insure your backup is up to date.  Messing with the OS at this level can lock you out where a factory default is the only recourse.

You can look in other directories with grep -Rl "another_user" to see if you find something I didn't.  The -R is recursive, so I don't recommend you do this from the root directory.  The l is a lower case letter L and give you the file name instead of the text.

If you can't find it, then the only other suggestion I have is to delete the entries in the other files and the home directories and see if you can then re-create the user.  Backup files before editing.