Oracle startup not possible - ORA-00845: MEMORY_TARGET not supported on this system

When i was doing 12CR2 isntallation on my VM. I have this error during startup..

Here it is..

ISSUE :

>startup

ORA-00845: MEMORY_TARGET not supported on this system 

SOLUTION:

The shared memory file system should have enough space to accommodate the MEMORY_TARGET and MEMORY_MAX_TARGET values.

To verify:

SQL> show parameter memory

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
hi_shared_memory_address             integer     0
memory_max_target                    big integer 6096M
memory_target                        big integer 6096M
shared_memory_address                integer     0

In UNIX/Linux, you will have to set the shared memory file system accordingly.

Verify:

$ df -h /dev/shm

Set:

$ mount -t tmpfs shmfs -o size=some_value_in_number_with_size /dev/shm

For example,

mount -t tmpfs shmfs -o size=4096m /dev/shm