1. Verfify that the Collector can read the system file /dev/kmem
> ls -l /dev/kmem
If 'others' do not have the read permission on this file, grant the necessary permission.
2. Sometimes the customer's site is configured so that the Oracle user is the only one who is able to attach to the shared memory, so it's not enough to be in the dba group. We suggest to reinstall PA with user oracle if possible or another option is if the permissions of the shared memory can be changed to allow alternate OS users in dba group.