What are the necessary authorizations and privileges for nfs mounting?

Hello,
I've been reading the System Administration Guide Security Services in order to create a Rights Profile that can perform mount/umount.
I can't use File System Management because it's too much.

I've done the following so far without success:

# /etc/security/prof_attr
...
Mounting Administration::::help=RtMountingAdmin.html
Database Administration::::profiles=Mounting Administration;help=RtDatabaseAdmin.html

# /etc/security/exec_attr
...
Mounting Administration:solaris:cmd:::/sbin/mount:privs=sys_mount
Mounting Administration:solaris:cmd:::/sbin/umount:privs=sys_mount

# /etc/user_attr
...
dba::::type=role;profiles=Database Administration
user2::::type=normal;roles=dba

When I use the root role I can successfully mount, but when I log in as user2 and switch to dba and then I can't: