After upgrading from 3.x to 4.x user names with a greater then 20 character limit can't login
'userPrincipalName' (UPN) needs to be set using Control Center. Control center is installed on your Windows server(s) to manage Unix settings. Please refer to the Administrators Guide for more on Control Center usage.
This behaviour can be overridden locally by modifying vas.conf and adding:
username-attr-name = userPrincipalName
for any QAS 4.x clients.
This can be accomplished with the following command being run before upgrading:
/opt/quest/bin/vastool configure vas vasd username-attr-name userPrincipalName