ERROR: failed to establish dependency between database and diskgroup resource

Issue:
ERROR: failed to establish dependency between database and diskgroup resource

has found in alert log

Explanation:
This means your database is not configured in clusterware. If you run command "crsctl stat res -t" you will not probably find it in the list.

Solution:
Register your database in clusterware like:
srvctl add database -d -o -p -a "," -r -s
Example:
srvctl add database -d standby -o /u01/app/oracle/product/11.2.0/db_1 -p /u01/app/oracle/product/11.2.0/db_1/dbs/spfilestandby.ora -a "DATA,FRA" -r PHYSICAL_STANDBY -s mount