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I'm also interested in using hugepages for oracle database in Oracle VM environment.
Little bit experimentation(xen source code) and googling give me xen boot parameter allowsuperpage=1
Then with superpages = 1 in vm.cfg it was able to allocate HugePages in PV domU.
domU OEL 6 with 2.6.39-200.29.2.el5uek
AnonHugePages: 0 kB
Hugepagesize: 2048 kB
I didn't find any documentation, howto or examples using this in Oracle VM ( or generally with Xen).
Any informations about benchmarks, stability and status of support of hugepages(superpages) in Oracle VM are welcome.
All this was done on Oracle VM 3.1
I don't "think" there is support on 3.1.1. There was support in 2.
Arn't you using 64 bit? and why would you choose huge pages over AMM? You really should consider AMM before you even attempt to run Huge Pages on a 64 bit platform.
Thank you Karel for valuable info
I will try in my environment and post some feedback here
I've got some informations about AMM and Hugepages(with ASSM).
We are preparing server (Oracle Vm hypervisor), that will host two large VMs (64bit OEL, 60+GB each). Each VM with cca 6 databases ( 2 with large SGA, rest smaller).
Ability to use huge pages give us the posibility to reduce pagetable walks and pagetablesize, so CPU and RAM savings.
I don't know what can give us the use of AMM in such a configuration?
AMM can partition the RAM between database instances.
I would definitely not recommend to use AMM in such configuration.
Please use MOS to read about Hugepages and AMM support. AMM is not supported with Hugepages. Only ASMM is supported.
You can read some valuable info about Linux, DB and memory management here:
have fun :)
You may want to read article 361323.1 before you choose to do such. Pay attention to the "What if Not Enough HugePages Configured?" section.
Either way... there is no talk of support for huge pages on 3.1.1. Have fun "tweaking your environment."