about shared memory 2G, 4G

biotwang

I am reading the oracle official 11gr2 quick install guide.

There is one problem I am not sure about it: in oracle, we are adviced to install oracle 11gr2 by using more than 2GB memory. And now in 11g, oracle is using shared memory management.

and I issue the command: df -h /dev/shm

1. <font size="1">login as: root
   
2. root@192.168.1.110's password:
   
3. Last login: Sun Oct  5 01:37:25 2014 from 192.168.1.13
   
4. [root@pd ~]# df -h /dev/shm
   
5. Filesystem            Size  Used Avail Use% Mounted on
   
6. tmpfs                 2.0G     0  2.0G   0% /dev/shm
   
7. [root@pd ~]#</font>
   

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My virtual Machine now is having 4GB memory.
so I wonder if oracle will only use 2GB which is from /dev/shm by using AMM, or it will enlarge the memory to 4GB as maximum?

Maclean Liu(刘相兵

FYI

解决Linux上11g的ORA-00845错误
http://www.askmaclean.com/archiv ... 94%99%E8%AF%AF.html

Maclean Liu(刘相兵

[oracle@PD009 trace]$ oerr ora 845
00845, 00000, "MEMORY_TARGET not supported on this system"
// *Cause: The MEMORY_TARGET parameter was not supported on this operating system or /dev/shm was not sized correctly on Linux.
// *Action: Refer to documentation for a list of supported operating systems. Or, size /dev/shm to be at least the SGA_MAX_SIZE on each Oracle instance running on the syste