One of the Oracle database server ‘s memory is to be upgraded from 48GB to 72GB, so some parameters should be adjusted to take advantage of the newly added memory.
Change memlock Parameter
Modify “memlock” parameter in /etc/security/limits.conf to 70G, which is for hugepage purpose. This parameter can be bigger than SGA, up to or even bigger than memory size.
oracle soft memlock 73400320 oracle hard memlock 73400320 grid soft memlock 73400320 grid hard memlock 73400320
Change nr_hugepages Parameter
Change parameter ‘nr_hugepages’ in /etc/sysctl.conf.
43GB memory( 60% of whole memory ) is allocated to hugepages.
vm.nr_hugepages = 22016
Change shmmni, shmall and shmmax values in /etc/sysctl.conf
a)Keep kernel.shmmni = 4096
b) kernel.shmall=13369344 (51GB) = 70% of whole memory divided by page size 4096.
c ) kernel.shmmax=38654705664( 36GB) = 50% of the whole memory size.
kernel.shmmni = 4096 kernel.shmall = 13369344 kernel.shmmax = 38654705664
Reconfigure SGA_TARGET and SGA_MAX_SIZE
Make sure the total SGA usage is less than vm.nr_hugepages = 22016( 43GB).
Make DBA Life Easy 