You may hit this error during some process such as: dbca, restore or startup database.

This error is meaning something wrong at your kernel settings.

Check first your current settings by using below command

# cat /etc/sysctl.conf | grep kernel | grep -v “#”

— Those parameters are for 60Gb RAM. You can use those settings as reference

kernel.shmall = 16039424
kernel.shmmax = 65697480704
kernel.shmmni = 4096

Then You can calculate what the kernel.shmall value should be with a formula as follows.

kernel.shmall = kernel.shmmax / kernel.shmmni