ORA-00845: MEMORY_TARGET not supported on this system

Problem

SQL> show parameter memory

NAME                                 TYPE        VALUE
------------------------------------ ----------- --------
hi_shared_memory_address             integer     0
memory_max_target                    big integer 3152M
memory_target                        big integer 3152M
shared_memory_address                integer     0

SQL> alter system set memory_max_target=8G scope=spfile;

System altered.

SQL> alter system set memory_target=8G scope=spfile;

System altered.

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.

SQL> startup
ORA-00845: MEMORY_TARGET not supported on this system

Solution

[root@prod ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             754G   42G  674G   6% /
tmpfs                 3.9G   88K  3.9G   1% /dev/shm

/dev/shm mount point size must be greater than or equal to value of MEMORY_TARGET parameter

So Increase the size of /dev/shm mount point

[root@prod ~]# umount -l /dev/shm/

[root@prod ~]# mount -t tmpfs shmfs -o size=8g /dev/shm

[root@prod ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda1             754G   42G  674G   6% /
shmfs                 8.0G     0  8.0G   0% /dev/shm

SQL> startup
ORACLE instance started.

Total System Global Area 8551575552 bytes
Fixed Size                  2215064 bytes
Variable Size            4093641576 bytes
Database Buffers         4429185024 bytes
Redo Buffers               26533888 bytes
Database mounted.
Database opened.

SQL> show parameter memory

NAME                                 TYPE        VALUE
------------------------------------ ----------- ---------
hi_shared_memory_address             integer     0
memory_max_target                    big integer 8G
memory_target                        big integer 8G

shared_memory_address                integer     0