Hello,

I'm testing virtualization of some Oracle servers.

I have 4.1.1 with CentOS 7.3 servers as hypervisors.

Typically on physical Oracle servers I configure huge pages for Oracle memory areas.

In particular I disable Transparent Huge Pages, because they are known to be in conflict with Oracle performances, both in RAC and in standalone configurations.

In RHEL systems I configure "transparent_hugepage=never" boot parameter, while in Oracle Linux OS uek kernels it is already disabled by default.

I notice that in CentOS 7.3, by default, transparent huge pages are configured:

[root@ov300 ~]# cat /proc/meminfo | grep -i huge

AnonHugePages: 17006592 kB

HugePages_Total: 0

HugePages_Free: 0

HugePages_Rsvd: 0

HugePages_Surp: 0

Hugepagesize: 2048 kB

[root@ov300 ~]#

I'm going to configure a VM with 64Gb of ram and with an Oracle RDBMS that would have 16Gb of SGA.

I suspect that I could have problems if I dont' change configuration at hypervisor level...

What do you think about this subject?

Is there any drawback if I manually configure the hypervisors to boot with the "transparent_hugepage=never" boot parameter?

Thanks in advance,

Gianluca