ORA-00845 MEMORY_TARGET not supported on this system 的解决

oracle11g数据库在执行dbca或者调整sga后重启oracle的时候可能会出现ORA-00845 MEMORY_TARGET not supported on this system 错误。
究其缘由就是Linux系统的shm的大小比SGA设置的小，形成的，距离来讲，SGA设置4G，而shm可能只有1G

网上提供两种解决办法：
0一、调整sga的大小，这个明显不是咱们所但愿的
0二、调整shm的大小，这样相对简单，具体操做以下
vi /etc/fstab
修改以下行的设置
tmpfs /dev/shm tmpfs defaults 0 0
改为
tmpfs /dev/shm tmpfs defaults,size=6G 0 0
保存退出
从新mount下shm使其生效
mount -o remount /dev/shm
经过df能够查看下，没有问题就能够继续安装数据库或者启动数据库了！

 

 

说明：服务器上有两个不一样数据库实例，启动一个实例的时候没问题。在启动第二个INSTANCE的时候报ORA-00845错误。该测试服务器仅8G内存。   tmpfs     默认是4G            4.0G  1.6G  2.4G  40% /dev/shm.  两个实例的使用内存应该超过了4G，因此安装网上这篇文章进行修改tmpfs，问题解决了。  可是新问题tmpfs 大小的限制如何肯定呢？观察一下内存使用在说吧

 

 

[oracle@BJRMANTS ~]$ su - root
Password:
[root@BJRMANTS ~]# vi /etc/fstab
[root@BJRMANTS ~]# df -g
df: invalid option -- 'g'
Try `df --help' for more information.
[root@BJRMANTS ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              20G  5.8G   13G  31% /
tmpfs                 4.0G  1.6G  2.4G  40% /dev/shm
/dev/sda1             485M   51M  409M  12% /boot
/dev/sda6             197G  160G   28G  86% /orabak
/dev/sda8              20G  6.2G   13G  34% /oracle
/dev/sda5             690G  549G  106G  84% /oradata
/dev/sda7             187G   75G  104G  42% /oralog
[root@BJRMANTS ~]# mount -o remount /dev/shm
[root@BJRMANTS ~]# df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda2              20G  5.8G   13G  31% /
tmpfs                 6.0G  1.6G  4.5G  26% /dev/shm
/dev/sda1             485M   51M  409M  12% /boot
/dev/sda6             197G  160G   28G  86% /orabak
/dev/sda8              20G  6.2G   13G  34% /oracle
/dev/sda5             690G  549G  106G  84% /oradata
/dev/sda7             187G   75G  104G  42% /oralog
[root@BJRMANTS ~]#

 

[oracle@BJRMANTS ~]$ export ORACLE_SID=oelncbi
[oracle@BJRMANTS ~]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.3.0 Production on Wed Dec 5 10:48:51 2012

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup;
ORA-00845: MEMORY_TARGET not supported on this system
SQL> exit
Disconnected
[oracle@BJRMANTS ~]$ export ORACLE_SID=oeldzdz
[oracle@BJRMANTS ~]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.3.0 Production on Wed Dec 5 10:49:33 2012

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> shutdown abort;
ORACLE instance shut down.
SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
[oracle@BJRMANTS ~]$ export ORACLE_SID=oelncbi
[oracle@BJRMANTS ~]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.3.0 Production on Wed Dec 5 10:49:51 2012

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup;
ORACLE instance started.

Total System Global Area  814227456 bytes
Fixed Size      2232760 bytes
Variable Size    452988488 bytes
Database Buffers   352321536 bytes
Redo Buffers      6684672 bytes
Database mounted.
Database opened.
SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
[oracle@BJRMANTS ~]$ export ORACLE_SID=oeldzdz
[oracle@BJRMANTS ~]$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.3.0 Production on Wed Dec 5 10:54:15 2012

Copyright (c) 1982, 2011, Oracle.  All rights reserved.

Connected to an idle instance.

SQL> startup;
ORACLE instance started.

Total System Global Area 2805977088 bytes Fixed Size      2231672 bytes Variable Size    603980424 bytes Database Buffers  2181038080 bytes Redo Buffers     18726912 bytes Database mounted. Database opened. SQL>