ORA-00845: MEMORY_TARGET not supported on this system

ORA-00845: MEMORY_TARGET not supported on this system

SQL> startup force;

ORA-00845: MEMORY_TARGET not supported on this system

SQL> !df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root
                       21G   17G  2.9G  86% /
tmpfs                1000M  420K 1000M   1% /dev/shm   <<<<------------------ br="" increase="" this="" value="">/dev/sda1             485M   41M  419M   9% /boot

Login with root user then run the below command for increasing the size

mount -t tmpfs shmfs -o size=2048m /dev/shm
Then check the file for above change
 vi /etc/fstab

/dev/mapper/VolGroup-lv_root /                       ext4    defaults        1 1
UUID=9a9b0c22-cacf-491c-ad27-b636c69da3cf /boot                   ext4    defaults        1 2
/dev/mapper/VolGroup-lv_swap swap                    swap    defaults        0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
shmfs                   /dev/shm                tmpfs   size=2048m      0 0   <<<<<<<<<---- add="" br="" following="" line="">
Then reboot the OS

SQL> startup ;
ORACLE instance started.

Total System Global Area 1255473152 bytes
Fixed Size                  1344652 bytes
Variable Size             754977652 bytes
Database Buffers          486539264 bytes
Redo Buffers               12611584 bytes
Database mounted.