ORA-02097: parameter cannot be modified because specified value is invalid

Alert log Entry

ORA-02097: parameter cannot be modified because specified value is invalid
ORA-00068: invalid value 4000 for parameter parallel_max_servers, must be between 0 and 3600
CKPT (ospid: 3277292): terminating the instance due to error 2097
Mon Jun 15 12:30:13 

Cause 1
It might be caused by the current system level change on the number of CPU which will shut down all the instances on the same server.

Solution

Just start the instances no need to worry oracle will take care of itself.

Cause 2

Related to parallel_max_servers wich is calculated 

PARALLEL_THREADS_PER_CPU * CPU_COUNT * concurrent_parallel_users * 5

and its value should range between 0 and 300.

Solution

Modify its value reasonably using alter system.