When moving or splitting a volume to a volume located on a different server, the administrator username and password must be valid on both servers. Otherwise, theor job fails.
Two possible causes of invalid matches are:
The administrator username that you used to log in to iManager and the original server is not configured for access on the destination server.
There is a case mismatch between the usernames, and the destination server is a Linux server, where usernames are case-sensitive.