Re: oracle on VM or non-VM ?!!

From: Neil Chandler <>
Date: Mon, 27 Nov 2017 09:57:38 +0000
Message-ID: <DB6PR10MB1815D27C27582AF784C20F7A85250_at_DB6PR10MB1815.EURPRD10.PROD.OUTLOOK.COM>

I do agree with much of what has been said, but disagree with other statements (around HA). Here's my take on things.

To address the OP's questions:

  1. Does Oracle on VM (type 1) have notable perf issues ? No. The CPU required by the hypervisor is negligable. Frequently disk is directly attached to the VM Guest through the hypervisor and there's no impact. The flexibility of using VM's far outweighs any minor negatives.
  2. Does license cost (or TCO) increase with VM/Oracle combination ? In an of itself, no. But this is a big risk factor. Using VMWare, no matter what anyone says about the legalities, will open you up to a protracted and potentially lawyer-enriching negotiation with Oracle following an audit, usually ending with the purchase of whatever they are pushing at the time [Exadata's/Cloud credits/etc] to make them "go away". You really need to go into using VMWare with your eyes open. Using Oracle Virtual Machine (OVM) allows you to hard-partition VM Guests within licensing constraints (make sure you do it right though!). OVM is OK.
  3. Is RAC on VM widely used ? I have several clients using RAC on OVM. There are a couple of special considerations with OVM, such as a server group per node, public IP heartbeat pings, etc
  4. RAC on non-VM or single instance on VM - which is good from a HA perspective ? Pre-11.2, RAC wasn't a HA option - pretty much the opposite. Now it is an excellent HA option but you need to understand your requirements. RAC is most relevant when you can't scale up any more or you want to have zero downtime patching (a major consideration these days given the amount of patching going on!) DataGuard is primarily (and always the preferred option for) DR but can be used as a HA option (especially with combined with Fast Start Fail Over). I know companies who have moved from RAC to DG with FSFO. On-line migrating single instance DB's on VM's to new hardware is straightforward and simple - but again, licensing and configuration is a major consideration here - even on OVM.
  5. If VM is advisable, VMware or Oracle VM - which works best overall ? VM is advisable. VMware is better but major licensing considerations. Nothing wrong with OVM, which is Xen hypervisor based. Until this month, the whole of AWS ran under Xen... Now they are using KVM too. I have no experience with KVM.

Neil Chandler

Database Guy.

From: <> on behalf of Iggy Fernandez <> Sent: 27 November 2017 03:10
To:; Cc:; Subject: Re: oracle on VM or non-VM ?!!

re: "Having said this, understand that Oracle will license based on the core count in the ESX host or hosts in a virtual machine cluster. They will not bother with niceties about virtual machines being restricted to individual nodes within a cluster, even if VMware says it will "back you up" on such a restriction. If any VM within a cluster runs Oracle, then all of the cores in the cluster will be licensed by Oracle. So, understanding this, it is important to designate a hypervisor cluster entirely for Oracle use only if concerned about maximizing Oracle licensing. Just my US$0.02..."

The VMware white paper is at

Understanding Oracle Certification, Support and Licensing ...<>
understanding oracle certification, support and licensing for vmware environments white paper may 2017

The germane sentence is "In particular, DRS Host Affinity rules can be used to run Oracle on a subset of the hosts within a cluster. In many cases, customers can use vSphere to achieve substantial licensing savings."

Another article worth reading is in the August 2017 issue of the NoCOUG Journal written by House of Brick and an intellectual property attorney. The article is specifically about cloud licensing but DRS host affinity rules are mentioned in passing, Vol. 31, No. 3 · AUGUST 2017 - NOCOUG<>
Vol. 31, No. 3 · AUGUST 2017 Oracle Cloud Revealed Brian Hitchcock takes notes. See page 8. Parallel RMAN Backups with Standard Edition Easy-Peasy says Norbert Debes.

Here are some interesting quotes from that article:

“Somewhere in your agreement is the following definition of the term Processor: Processor shall be defined as all processors where the Oracle programs are installed and/or running. This is the most fundamental and important definition in your agreement.”

“Installed is a past-tense activity that presently applies. Running is a present-tense activity. There is nothing indicating a license requirement for prospective activities (things that might happen in the future), no matter how easy they may be to bring about.”

“The ... policy document is a non-contractual reference. It is excluded by the Entire Agreement clause of your master agreement with Oracle.”

“The main point that I would like all NoCOUG readers to take from this discussion is that your contract with Oracle is what matters. You do not have to do something that is not in the best interest of your organization when it is outside of the scope of your binding agreement with Oracle.”

Iggy Fernandez


Cellphone: (925) 478 3161

Blog: Explaining the Explain Plan<>

Author of Beginning Oracle Database 12c Administration<>

Editor of the NoCOUG Journal<>

From: <> on behalf of Tim Gorman <> Sent: Sunday, November 26, 2017 12:27 PM To:
Cc:; Subject: Re: oracle on VM or non-VM ?!!

Expanding on a few of Andrew's points, I can't believe that it has been almost 10 years now, but it has...

9 years ago, I was hired by our local rapid-transit agency specifically to assist in deploying Oracle RAC and Oracle DataGuard. At that time, they had also begun using VMWare ESX with HA, VMotion, and Storage VMotion for their internal infrastructure.

Oracle RAC is a scalability option only -- it was not designed as an HA solution and any HA capabilities it possesses are necessary for it to simply exist. So, if more horsepower is needed, then scale up with hardware until the limit for the chosen hardware platform is reached. Beyond that limit, use Oracle RAC to continue to scale up across servers.

For database high-availability (HA), use Oracle DataGuard. Period. Full stop.

Received on Mon Nov 27 2017 - 10:57:38 CET

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