Cause

shmall is the total amount of shared memory, in pages, that the system can use at one time.

Solution

Set shmall equal to the sum of all the SGAs on the system, divided by the page size.

The page size can be determined using the following command:

$ getconf PAGE_SIZE
4096

For example, if the sum of all the SGAs on the system is 16Gb and the result of '$ getconf PAGE_SIZE' is 4096 (4Kb) then set shmall to 4194304 pages

As the root user set the shmall to 4194304 in the /etc/sysctl.conf file:

kernel.shmall = 4194304

then run the following command:

# sysctl -p
# cat /proc/sys/kernel/shmall
4194304