Oracle11G，MEMORY_TARGET的设置问题，求大神指导
oracle 11g安装后，早上还能登陆，下午就不行了，求大神指导。

[oracle@r720-2 ~]$ sqlplus

SQL*Plus: Release 11.2.0.1.0 Production on Mon Jul 1 20:03:07 2013

Copyright (c) 1982, 2009, Oracle. All rights reserved.

Enter user-name: sys as sysdba
Enter password:
Connected to an idle instance.
SQL> startup;
ORA-00845: MEMORY_TARGET not supported on this system

MEMORY_TARGET不知道在哪设置，根据网上资料，设置了系统参数，但依然无效

[root@r720-2 ~]# mount -o remount /dev/shm
[root@r720-2 ~]# df -h /dev/shm/
Filesystem Size Used Avail Use% Mounted on
shmfs 20G 0 20G 0% /dev/shm

想重启数据库也报错~~~
SQL> shutdown immediate;
ORA-01034: ORACLE not available
ORA-27101: shared memory realm does not exist
Linux-x86_64 Error: 2: No such file or directory
SQL> startup mount
ORA-00845: MEMORY_TARGET not supported on this system
Oracle 数据库
[解决办法]
推荐你看看，希望对你有帮助
http://space.itpub.net/22779291/viewspace-693744

[解决办法]

引用:

这台机器好奇怪，CPU很空闲，但是MEM却被占满了，求高手解答

内存泄露了吧，啥系统啊？
[解决办法]
（1）登陆orcl数据库
SQLPLUS SYS/SYS@orcl AS SYSDBA
(2)设置内存大小
ALTER SYSTEM SET MEMROY_MAX_TARGET=500M SCOPE=SPFILE;（SCOPE=SPFILE表示写如SPFILE文件，在数据库重启后生效）
(3) 设置自动分配的内存大小
ALTER SYSTEM SET MEMORY_TARGET = 500M SCOPE=SPFILE;（表示自动调节PGA和SGA的总大小为500M）
ALTER SYSTEM SET SGA_TARGET =0 SCOPE=SPFILE;

ALTER SYSTEM SET PGA_AGGREGATE_TARGET =0 SCOPE=SPFILE;
（4）关闭数据库
SHUTDOWN IMMEDIATE
（5）重启数据库EXP1使配置生效
STARTUP

[解决办法]
我以前也碰到过这个错误，我是按下面的方法搞定的，我假设你的实例名为orcl
在linux下执行：
1、cd $ORACLE_HOME/dbs
2、sqlplus / a sysdba
3、create pfile from spfile;
然后修改pfile里面的内容，将memery_target修改为sga_target 和 pga_aggregate_target，一个256M，一个200M。
并去掉开始所有的orcl.的选项。

5、startup pfile='initorcl.ora'
6、create spfile from pfile='initorcl.ora'
7、startup force
[解决办法]

引用:

问题是解决了，是因为服务器内存不够导致我服务启不来。我用7楼的方法，查看到我
*.memory_target=54087647232
应该是55G，于是我调整了
vi /etc/fstab--调整共享内存大小
mount /dev/shm--执行可用
df -h /dev/shm--验证值为60G，
然后在oracle用户下startup就把服务器启动了。

但是我想把这个memory_target值改小，我怕后面资源不够，又导致我服务启不了，是不是直接修改这个值就可以，还需要调整其他值吗？跟表空间这些有关系吗？

你的sga_target sga_max_size 设置是多少？

摘入一段官方文档的描述：

If MEMORY_TARGET is set to a non-zero value:

If SGA_TARGET and PGA_AGGREGATE_TARGET are set, they will be considered the minimum values for the sizes of SGA and the PGA respectively. MEMORY_TARGET can take values from SGA_TARGET + PGA_AGGREGATE_TARGET to MEMORY_MAX_TARGET.
If SGA_TARGET is set and PGA_AGGREGATE_TARGET is not set, we will still auto-tune both parameters. PGA_AGGREGATE_TARGET will be initialized to a value of (MEMORY_TARGET-SGA_TARGET).
If PGA_AGGREGATE_TARGET is set and SGA_TARGET is not set, we will still auto-tune both parameters. SGA_TARGET will be initialized to a value of min(MEMORY_TARGET-PGA_AGGREGATE_TARGET, SGA_MAX_SIZE (if set by the user)) and will auto-tune subcomps.
If neither is set, they will be auto-tuned without any minimum or default values. We will have a policy of distributing the total memory set by memory_target parameter in a fixed ratio to the the SGA and PGA during initialization. The policy is to give 60% for sga and 40% for PGA at startup.