/dev/shm過小導緻ORA-00845錯誤解決方法

The workaround, if you encounter the ORA-00845 error, is to increase the /dev/shm

mountpoint size.

For example:

# mount -t tmpfs shmfs -o size=7g /dev/shm

To make this change persistent across system restarts, add an entry in /etc/fstab

similar to the following:

shmfs /dev/shm tmpfs size=7g 0

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 must be at least the greater of the MEMORY_MAX_TARGET and MEMORY_

TARGET parameters for each Oracle instance on the computer. If the MEMORY_MAX_

TARGET parameter or the MEMORY_TARGET parameter is set to a non-zero value, and

an incorrect size is assigned to the shared memory, it results in an ORA-00845 error at

startup. On Linux systems, if the operating system /dev/shm mount size is too small

for the Oracle system global area (SGA) and program global area (PGA), it will result

in an ORA-00845 error.

The number of file descriptors for each Oracle instance must be at least

512*PROCESSES. The limit of descriptors for each process must be at least 512. If file

descriptors are not sized correctly, you will see an ORA-27123 error from various

Oracle processes and potentially Linux Error EMFILE (Too many open

files)in non-Oracle processes.

To determine the amount of shared