Oracle boot prompt ORA-00845: memory error Solution

Today, the VM memory is reduced a little, and the following error occurs when the data is started:

SQL> startup

ORA-00845: MEMORY_TARGET not supported on this system

I guess it should be the problem of system memory conflicts with sga. Then I checked it on the Internet. It is true that:

The official analysis from Oracle is:

Starting with Oracle Database 11g, the Automatic Memory Management feature requires more shared memory (/dev/shm) and file descriptors. the size of the shared memory shocould be at least the greater of MEMORY_MAX_TARGET and MEMORY_TARGET for each Oracle instance on the computer. if MEMORY_MAX_TARGET or MEMORY_TARGET is set to a non zero value, and an incorrect size is assigned to the shared memory, it will result in an ORA-00845 error at startup.

That is, because the size of the SGA exceeds the size of the Operating System/dev/shm:

There are only two ways to solve this problem. One is to modify the initialization parameter so that the SGA setting in the initialization parameter is smaller than/dev/shm, another method is to adjust the size of/dev/shm.

1. Modify the size of/dev/shm

Root Login

1. # Vi/etc/fstab
2. Tmpfs/dev/shm tmpfs ults,Size= 320 M 0 0

Change the above size to a value greater than the sga size. Restart or re-mount

# Umount/dev/shm

# Mount/dev/shm

Ii. Modify the sga size

AlterSystemSetSga_max_size = ***** scope = spfile;

Then restart the database.