Oracle 12c Database Setup shmall Kernel Parameter
Hi! This Tip shows you How to Setup shmall Kernel Parameter for Oracle 12c Database Installation on GNU/Linux Systems.
Following the Oracle Documentation shmall should be Set to 40% of the Physical Memory in Pages.
So to Find the Memory Size in Pages:
getconf -a | grep _PHYS_PAGES
And to Find the Physical Memory RAM Size in Kb:
cat /proc/meminfo | grep MemTotal
This because:
_PHYS_PAGES = [RAMKB] / 4
And the 40% is rightly:
[RAMKB] / 4 * 4 / 10 = [RAMKB] / 10
Then a Good approximation is found simply with the formula:
[RAMKB] / 10
So on a 16Gb RAM System about:
16364544 / 10 = 1636454