Reasons why not to use Oracle VM…

I get a little bit cranky about some statements posted on the (Oracle maintained?) blog “Oracle VM Blog”. Not because they are not true, but more about people tend to use them out of context. A lot of people I know state afterwards, after reading those pointers, OK, so “Oracle VM is 3 times faster than other virtualization products”. They do not read what it actually says (also now on the Oracle VM Blog). It states: “Greater efficiencies—Three times more efficient than the other, leading server virtualization product.” (aka VMware?) or “Three times greater efficiency than current x86 based server virtualization products”.

Here we go (again). It depends…

First off all Oracle VM, as far as I currently know, is based on the XEN hypervisor. As far as I know this is / was an open source project, but lately Citrix Systems acquired XenSource (22/10/2007), and part of the project split and moved to the Xen project . Essentially Oracle VM has the same characteristics as the Xen hypervisor. Said this, this means that it has (at current state) the benefits and the lacks of the Xen hypervisor (v 3.1.1). Xen was initially developed with only the possibility of virtualizing Linux environments in mind. MS Windows guests are not so great regarding performance in comparison to “other” vitualization products.

In the Oracle FAQ whitepaper on www.oracle.com it clearly states:

Will the performance of Microsoft Windows running on Oracle VM be similar to the performance of Enterprise Linux running on Oracle VM?

No. Currently, Microsoft Windows runs significantly slower on Oracle VM than it does on native hardware. However, Oracle is developing paravirtualized Windows drivers that will substantially improve the performance of Windows on Oracle VM.

So, if Windows guests are important to you, you might want to wait.

…but said that, something has radically changed since Oracle VM. Oracle know fully undoubtedly supports a virtualization method and this is only good news, especially because I really love the possibilities given by virtualization technology, that I as a private person, in terms of hardware, couldn’t effort. Nowadays I can actually build a RAC system with low cost hardware.

Oracle VM comes in two parts: Oracle VM Server and Oracle VM Manager. The following statement in the Oracle VM FAQ whitepaper,

“Consisting of open source server software and an integrated Web browser-based management console”

gives me the reasons to believe that Oracle will contribute to the open source Xen community via co-development of the Oracle VM Server part, but that this could not be the case regarding Oracle VM Manager. In my mind, this would be as expected because I would integrate the manager part in Oracle’s flagship Oracle Enterprise Manager Grid Control. The disadvantage of this would / could be that you would be licensed bound (and OEM grid doesn’t come cheap).

So, all in all, when put my mindset in perspective, using Oracle VM would be great when your environment is dedicated to Oracle solutions and fully linux based. You get the advantage of a fully by Oracle supported environment, cheaper and more powerful than other virtualization (non-Xen) products. Because Oracle has a great development team behind the Oracle VM product, it probably will out run Xen competitors in the end as well (but currently I can’t find hard proof on the internet for this). One thing is currently clear, the Oracle VM virtualization support is cheaper than the “other” virtualization market competitor.

I breath, eat, swim, love, am nerd-ish about Oracle software. I support people already since 10 – 15 years as an Oracle DBA (and still love my job), but I think that people should realize that every great solution comes with a prize. If you try to make a consistent, well thought through, maintainable and balanced decision, taken into account the pro’s and cons, then you are more or less sure that the solution will fit 99% of your needs. Although you will never gain up to the desired 100%. This is the daily part of dealing with software (issues). You can always advice the customer to try a “ctrl-alt-del” approach and see if the problem has solved. In the end it is stuff made by us humans, so error prone.

8-)

Marco

Probably overkill, but this is my personal website. Views given here are my own and maybe do not reflect the general opinion of my current employer.