Solaris Cluster starts or stop Oracle database using credentials of a specified user in Oracle Database.
If you have issues with starting of Oracle Database resource and see ORA-28001 error message in /var/adm/messages it means that users which is used by Solaris Cluster to start Oracle database password is expired.
To resolve the issue reset the password of the Oracle database user
SQL> alter user user_name identified by password
and change connection string in solaris Clsuter using following command
-bash-3.2 # /usr/cluster/bin/clresource set -p Connect_string="user/password" oracle_resource