Post date: 01-Sep-2009 09:24:56
Metalink Doc ID: 465048.1
Oracle Server - Standard Edition - Version: 11.1.0.6 to 11.2.0.2
Linux x86-64
Customer may receive the below error messages on Linux Machines ::
SQL> connect sys as sysdba
Enter password:
Connected to an idle instance.
SQL> STARTUP NOMOUNT PFILE="/opt/oracle/admin/day/pfile/day2.ini";
ORA-00845: MEMORY_TARGET not supported on this system
On Linux systems, insufficient /dev/shm mount size for PGA and SGA.
AMM (Automatic Memory Management) is a New feature in 11G which manages both SGA and PGA
together. Its is managed by MMAN, same as with 10g AMM
MEMORY_TARGET is used instead of SGA_TARGET
MEMORY_MAX_TARGET is used instead of SGA_MAX_SIZE (defaults to MEMORY_TARGET )
It uses /dev/shm on Linux
If max_target set over /dev/shm size, you may get the below error message ::
ORA-00845: MEMORY_TARGET not supported on this system
If you are installing Oracle 11G on a Linux system, note that Memory Size (SGA and PGA), which sets
the initialization parameter MEMORY_TARGET or MEMORY_MAX_TARGET, cannot be greater than the shared memory filesystem (/dev/shm) on your operating system.
NOTE:
This error may also occur if /dev/shm is not properly mounted. Make sure your df output is similar to the following:
$ df -k
Filesystem 1K-blocks Used Available Use% Mounted on
...
shmfs 6291456 832356 5459100 14% /dev/shm
Increase the /dev/shm mountpoint size.
For example:
# mount -t tmpfs shmfs -o size=7g /dev/shm
Also, to make this change persistent across system restarts, add an entry in /etc/fstab similar to the following:
shmfs /dev/shm tmpfs size=7g 0
NOTE: You should check with your OS Administrator and/or alert.log for information on "best" size fo shm.
CONFIGURATION ; INITIALIZATION~PARAMETERS ; PFILE ; MEMORY_TARGET ;