I have been trying to switch from oracle AMM to ASMM huge pages. I have done the following changes on RHEL 6
Added following entry in /etc/sysctl.conf ( as suggested by hugepages_setting.sh )
vm.nr_hugepages=777
Added following entry in /etc/security/limits.conf
oracle soft memlock 2831155
oracle hard memlock 2831155
rebooted the server
changed oracle parameters memory_target, memory_max_target, sga_target, sga_max_target, use_large_pages to specific values.
After a database restart, I can see the following:
[root@rheloracle ~]# grep -i huge /proc/meminfo
AnonHugePages: 0 kB
HugePages_Total: 777
HugePages_Free: 8
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
And when I shutdown the database I could see the HugePages_Free is equal to HugePages_Total.
[root@rheloracle ~]# grep -i huge /proc/meminfo
AnonHugePages: 0 kB
HugePages_Total: 777
HugePages_Free: 777
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
Looks like HugePage configuration at db level and o/s level are in sync and in use. But all the examples and documents (i have referred) indicate that HugePages_Rsvd should have a non zero value after enabling huge pages. But same is not happening in my case. Can you please suggest if I am missing something or it's normal to have HugePages_Rsvd 0.
(I am running oracle 18c xpress edition on RHEL6)
Asked by Prem
(243 rep)
Aug 20, 2020, 05:00 AM
Last activity: Jan 26, 2021, 09:07 PM
Last activity: Jan 26, 2021, 09:07 PM