Today morning, My one of the friend reported me oracle error: “ORA-00845: MEMORY_TARGET not supported on this system” He has installed Oracle 11g R2 & not able to startup newly created database on newly installed oracle.

After diagnosis, I came to know it was the problem with ‘tmpfs’ with low space available.

This error pops up due to we are using Automatic Memory Management (AMM) feature of Oracle 11g R2 on shared memory filesystem (shmfs) which is found less than required.

Solutions for the mentioned error:

• Increase value of oracle parameter: ‘memory_max_target’ & ‘memory_target’ and try to startup database.
• If above not working than delete ‘memory_target’ parameter from parameter file & try to startup database.
• If above not working than increase ‘tmpfs’ space.

// Trying to startup oracle database:

[oracle@localhost ~]$ sqlplus “/ as sysdba”
SQL*Plus: Release 11.2.0.1.0 Production on Wed May 28 09:52:19 2014
Copyright (c) 1982, 2009, Oracle. All rights reserved.

Connected to an idle instance.

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

// Ensure ‘tmpfs’ space available with the help of ‘df -h’ linux command:

[root@localhost ~]# df -h

Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root 18G 14G 3.3G 81% /
tmpfs 497M 255M 242M 52% /dev/shm
/dev/xvda1 485M 61M 400M 14% /boot

// Available space of ‘tmpfs’ is not enough to start oracle, Issue the following command to increase size of ‘tmpfs’:
[root@localhost ~]# mount -t tmpfs shmfs -o size=3500m /dev/shm

// Ensure your changes by following:
[root@localhost ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/VolGroup-lv_root 18G 14G 3.3G 81% /
tmpfs 3.5G 0 3.5G 0% /dev/shm
/dev/xvda1 485M 61M 400M 14% /boot
shmfs 3.5G 0 3.5G 0% /dev/shm

// To make above changes persistence do edit your ‘/etc/fstab' file as follows:

cat  /etc/fstab

…
tmpfs          /dev/shm         tmpfs          size=3500m         0 0
…

 

// Startup database:
SQL*Plus: Release 11.2.0.1.0 Production on Wed May 28 10:05:45 2014
Copyright (c) 1982, 2009, Oracle. All rights reserved.
Connected to an idle instance.

SQL> startup
ORACLE instance started.
Total System Global Area 409194496 bytes
Fixed Size 2213856 bytes
Variable Size 310380576 bytes
Database Buffers 92274688 bytes
Redo Buffers 4325376 bytes
Database mounted.
Database opened.

Cheers!! Database has been opened successfully. 🙂

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Thanking you.
Have a easy life ahead.