数据库从10.2.0.5升级到11.2.0.4后，启动memory_target时报错：ORA-00845: MEMORY_TARGET not supported on this system

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

Starting with Oracle Database 11g, the Automatic Memory Management feature requires more shared memory (/dev/shm)and file descriptors. The size of the shared memory should be at least the greater of MEMORY_MAX_TARGET and MEMORY_TARGET for each Oracle instance on the computer. If MEMORY_MAX_TARGET or MEMORY_TARGET is set to a non zero value, and an incorrect size is assigned to the shared memory, it will result in an ORA-00845 error at startup.

说白了就是 MEMORY_MAX_TARGET 的设置不能超过 /dev/shm 的大小：


[grid@athenadb1 ~]$ df -h
文件系统              容量  已用 可用 已用% 挂载点
/dev/mapper/VolGroup00-LogVol00
                      416G   33G  362G   9% /
/dev/sda1             190M   29M  152M  16% /boot
tmpfs                  95G  437M   95G   1% /dev/shm

但是memory_target=134G


解决办法：将/dev/shm改为140G，然后重启系统


[root@athenadb2 ~]# vi /etc/fstab 
/dev/VolGroup00/LogVol00 /                       ext3    defaults        1 1
LABEL=/boot             /boot                   ext3    defaults        1 2
tmpfs                   /dev/shm                tmpfs   defaults,size=140G  0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
/dev/VolGroup00/LogVol01 swap                    swap    defaults        0 0
/dev/mapper/BACKDISKp1  /backup                 ext3     defaults        1 1



[grid@athenadb1 ~]$ df -h
文件系统              容量  已用 可用 已用% 挂载点
/dev/mapper/VolGroup00-LogVol00
                      416G   33G  362G   9% /
/dev/sda1             190M   29M  152M  16% /boot
tmpfs                 140G   16G  125G  11% /dev/shm