ORA-27102: out of memory Linux-x86_64 Error: 28: No space left on device

 ORA-27102: out of memory Linux-x86_64 Error: 28: No space left on device

When i try to increase sga_target from 50GB to 60GB i got above error.

the reason is shmall value is not configured accordingly for the SGA size.

[root@test_db_LAB ~]$  cat /etc/sysctl.d/97-oracle-database-sysctl.conf|grep  kernel.shmmni

kernel.shmmni = 4096

[root@test_db_LAB ~]$  cat /etc/sysctl.d/97-oracle-database-sysctl.conf|grep  kernel.shmall

kernel.shmall = 23592960

[root@test_db_LAB ~]$  cat /etc/sysctl.d/97-oracle-database-sysctl.conf|grep  kernel.shmmax

kernel.shmmax = 105374182400

Calculation for kernel.shmall  should be (SGA in bytes)/4096(kernel.shmmni)  = 15728640

as root user, set value 15728640 for shmall in file /etc/sysctl.d/97-oracle-database-sysctl.conf.

as root user, apply the changes. 

/sbin/sysctl -p /etc/sysctl.d/97-oracle-database-sysctl.conf

start the database.