Stefan -
By default all VMs are included in defau;t sub-client.
You can assign a given VM to another subclient.
Then give it a different backup policy that doesn't back it up on the same schedule.
You should back up the SQL data separately, using the iDataAgent for MSSQL.
I hope this response has been helpful to you.
At your service,
Eugene E. Kashpureff, Sr.
Independent NetApp Consultant, K&H Research http://www.linkedin.com/in/eugenekashpureff
Senior NetApp Instructor, IT Learning Solutions http://sg.itls.asia/netapp
(P.S. I appreciate points for helpful or correct answers.)