SQL> startup mount pfile='/tmp/initdlfasp12.ora' ORA-27102: out of memory Linux-x86_64 Error: 28: No space left on device This as you can see is on Linux x86 with 64 bit processor. We got this error after we changed SGA on 10gR2 database. So was sure that this is something to do with the OS. Parameters to check for this are shmall. shmall is the total amount of shared memory, in pages, that the system can use at one time. $cat /proc/sys/kernel/shmmax 53687091200 $ getconf PAGE_SIZE 4096 As per Oracle SHMALL should be set to the total amount of physical RAM divided by page size. Our system has 64GB memory, so change kernel.shmall = 1024 * 1024 * 1024 * 64 / 4096 = 16777216 Once this value is calculated you can modify Linux system configuration file directly. $ su - root vi /etc/sysctl.conf file: kernel.shmall=16777216 and # sysctl -p Once this is done the database was started without any problem.