ORA-00845: MEMORY_TARGET not supported on this system

ORA-00845: MEMORY_TARGET not supported on this system

When I was opening 12cR2 database after installation I get a ORA-00845 error.

Because I am using Automatic Memory Management (AMM) feature & If Shared Memory file system (shmfs) is not big enough to accommodate memory_target and memory_max_target. Then i will get this error.

[oracle@db12a -] $ export ORACLE_SID=orcl

[oracle@db12a -] $ sqlplus / as sysdba

SQL*Plus: Release 12.2.0.1.0 Production on Tue Nov 6 12:23:37 2018

Copyright (c) 1982, 2016, Oracle.

All rights reserved.

Connected to an idle instance.

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

[root@db12a ]# df -h

Filesystem 	Size  Used Avail Use Mounted on

dev/sda2	916   25G  62G   29%  / 

tmpfs		1.1G  520K 1.16  1    /dev/sh 

/dev/sdal	190M 1134  63M   65%  /boot

/dev/sda3	9.5G 1.6G  7.5G  18%  /tmp

12.2-data	1846 1416  446   77%  /media/sf_12.2-data

/dev/sr0	56M   56M    0  100%  /media/Vox GAS 5.2.20

There are two possible ways to remove the ORA-00845 error.

Reduce the value for the memory_target parameter Or Increase the temporary memory allocation on the server.

I will increase the Shared Memory file system (shmfs). For this I will mount with increased space for tmps.

[root@db12a -]# mount -t tmpfs shmfs - size 2g /dev/shm 

Now Check the filesystem size.

[root@db12a ]# df -h

Filesystem Size Used Avail Use Mounted on

dev/sda2 916 25G 62G 29% /

tmpfs 2.0G 0 2.0G 0% /dev/shm

/dev/sdal 190M 1134 63M 65% /boot

/dev/sda3 9.5G 1.6G 7.5G 18% /tmp

12.2-data 1846 1416 446 77% /media/sf_12.2-data

/dev/sr0 56M 56M 0 100% /media/Vox GAS 5.2.20

shmfs 2.0G 0 2.0G 0% /dev/shm

But  same changes  I will add in /etc/fstab  file for permanent effect.

[root@db12a ]# vim /etc/fstab

#
# /etc/fstab
# Created by anaconda on Mon Nov 5 07:52:06 2018
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=ddd1344e-d224-4100-8b4e-de0afd1a5080 / ext4 defaults 1 1
UUID=4bb5af18-fdc2-45ff-bdad-452db3c681c4 /boot ext4 defaults 1 2
UUID=65903f13-b00f-4ea4-8556-3ad72b52b508 /tmp ext4 defaults 1 2
UUID=46573343-1a4c-421a-befc-13404c61d08e swap swap defaults 0 0

#tmpfs /dev/shm tmpfs defaults 0 0

tmpfs /dev/shm tmpfs size=2g 0 0-----this line i have updated

devpts /dev/pts devpts gid=5,mode=620 0 0

sysfs /sys sysfs defaults 0 0

proc /proc proc defaults 0 0

The mount command mounts a storage device or file system making it accessible and attaching it to an existing directory structure.

[root@db12a ~]# mount -a

Now Start the database.

[root@db12a ~]# su - oracle

[oracle@db12a ~]$
[oracle@db12a ~]$ export ORACLE_SID=orcl
[oracle@db12a ~]$ sqlplus / as sysdba

SQL*Plus: Release 12.2.0.1.0 Production on Wed Nov 7 22:43:17 2018

Copyright (c) 1982, 2016, Oracle. All rights reserved.

Connected to an idle instance.

SQL> startup
ORACLE instance started.

Total System Global Area 1174405120 bytes
Fixed Size 8619984 bytes
Variable Size 838862896 bytes
Database Buffers 318767104 bytes
Redo Buffers 8155136 bytes
Database mounted.
Database opened.

Now Error  (ORA-00845: MEMORY_TARGET not supported on this system) is Resolved.

Check regularly my post and give feedback & comments!!!!.

Thanks

Ahmad (Riaz Ahmad Ansari)

OCE In (11g R2 RAC)

OCP In (11g/10g/9i)