Use the mem_verify.sh script to help verify and configure HugePages on Linux servers used for Oracle.

Example usage:

[oracle@oravm01 hugepages]$ ./mem_verify.sh

OS: totalmem: 5201707008

   hugepages: 800

hugepage_bytes: 1677721600

soft_memlock: 41943030
    in bytes: 42949662720
hard_memlock: 41943030
    in bytes: 42949662720

      shmmax: 68719476736
      shmall: 4294967296
shmall bytes: 17592186044416

    pagesize: 4096

The following should be true:

shmmax <= available memory shmall <= available memory SGA <= hugepages SGA <= memlock < available memory

Oracle:

granulesize: 16777216 SGA: 1660944384

Warning: shmmax of 68719476736 > totalmem of 5201707008 Set shmmax to 5201707008 or less

Warning: shmall of 4294967296 ( 17592186044416 bytes ) > totalmem of 5201707008 Set shmall to 1269948 or less

Warning: SGA:SOFT_MEMLOCK:TOTALMEM imbalance Should be: SGA <= soft_memlock < Total Memory Adjust 'oracle soft memlock 5078768' in /etc/security/limits.conf

Warning: SGA:HARD_MEMLOCK:TOTALMEM imbalance Should be: SGA <= hard memlock < Total Memory Adjust 'oracle hard memlock 5078768' in /etc/security/limits.conf

Warning: Configured SGA is larger than Configured HugePages Set HugePages to 792 or more Adjust vm.nr_hugepages=792 in /etc/sysctl.conf

use 'sysctl -p' to reload configuration changes to hugepages config will require server reboot

All OK if no warnings shown

memory_target and memory_max_target are not compatible with HugePages Estimating SGA and PGA settings for any instances found using the memory target parameters