ORA-00845-MEMORY_TARGETnotsupportedonthissystem

1.1. ORA-00845

ORA-00845: MEMORY_TARGET not supported onthis system

00845,000 00, "MEMORY_TARGET notsupported on this system"

// * Cause: The MEMORY_TARGET parameter wasnot supported on this operating system or/dev/shm was not sized correctly onLinux.

// * Action: Refer to documentation for alist of supported operating systems. Or, size/dev/shm to be at least theSGA_MAX_SIZE on each Oracle instance running on the system.

Error Message

In the ASM environment, an error is reported when the oracle instance is started.

SQL> startup

ORA-00845: MEMORY_TARGET not supported onthis system

View logs

Sun Mar 30 14:28:07 2014

Adjusting the default value of parameterparallel_max_servers

From 640 to 185 due to the value ofparameter processes (200)

Starting ORACLE instance (normal)

WARNING: You are trying to use theMEMORY_TARGET feature. this feature requires the/dev/shm file system to bemounted for at least 19327352832 bytes. /dev/shm is either not mounted or ismounted with available space less than this size. please fix this so thatMEMORY_TARGET can work as expected. current available is 16536903680 and usedis 288894976 bytes. ensure that the mount point is/dev/shm for this directory.

Memory_target needs larger/dev/shm

View/dev/shm partition information

Filesystem Type Size Used Avail Use % Mounted on

Tmpfs 16G 14.2G 1.8G 89%/dev/shm

Adjust the/dev/shm partition size:

# Vim/etc/fstab

Tmpfs/dev/shm tmpfs ults, size = 20G 0 0

View the processes using the/dev/shm partition:

# Lsof/dev/shm -- the ASM instance is in use

Close the ASM instance (confirmed to close ):

# Sqlplus-S/as sysasm

-- Check the Session of the current connection

Selectusername, status, server, type, program, action, logon_time, state from v $ session;

-- Confirm that the ASM instance can be closed

Shutdown normal

Reload the/dev/shm partition:

# Mount-o remount/dev/shm

View the/dev/shm partition size:

# Df-hT | grep shm

Tmpfs 20G 19G 1.8G 92%/dev/shm

Start an Oracle instance:

# Id

Oracle

# Sqlplus-S/as sysdba

Startup

Started successfully.