When trying to start-up a database received below error on a REHL 5.x
ORA-27102: out of memory
Linux-x86_64 Error: 28: No space left on device
By looking the error, you might think that it is a space issue. But note that the actual error is “Out of Memory”.
You can also check available memory on the server and you should see enough FREE memory.
total used free shared buffers cached
Mem: 125 80 45 0 0 88
-/+ buffers/cache: 36 89
Swap: 23 2 21
The server has enough memory but out of shared memory pages that can be used system wide. You should increase the kernel.shmall value to fix the issue.
The default size for SHMALL in Red Hat Enterprise Linux 2.1, 3, 4 and 5 is 2097152. Refer My Oracle Support document ID 169706.1 for recommended values.
Once you change the value you no need to reboot the server, you should reload the system configuration file as root using below command
$ sysctl –p
Hope this should resolve your issue
Satishbabu Gunukula, Oracle ACE