Having tried, and failed, to kill Red Hat Linux with Unbreakable Linux, Oracle is now sneaking up on CentOS.

Larry Ellison's database giant is now touting a piece of code it claims will let you convert your CentOS machine into Oracle Linux systems with no strings attached.

Well, there is one catch: switching actually provides little discernible advantage over CentOS, except the opportunity to give Oracle your money for its support.

And it's a prospect CentOS users are widely turning down, saying they won't switch to Oracle Linux because they don't trust Oracle and also because of the company's poor standing as a member of the open-source community.

Oracle's Larry Ellison launched Unbreakable Linux in 2006 to squeals of delight – his own – at OpenWorld, with the plan to swap out Red Hat Enterprise Linux by offering binary compatibility wrapped with Oracle's support. Six years on, Oracle has 7,000 Oracle Linux customers.

Oracle has now switched its attention to CentOS, the RHEL derivative.

The script Oracle is touting is here, and the story it's selling is simple. "We've created a simple script to switch your CentOS systems to Oracle Linux. We think you'll like what you find, and we'd love for you to give it a try," Oracle says here.

The USP boils down to: binary compatibility with CentOS; access to Ksplice, which was bought by Oracle last year, for kernel splicing; access to DTrace from Solaris to find system problems; and, er, faster updates to the kernel than under CentOS.

All this is totally free because Oracle Linux is free. The only cost to you? Support, the real differentiator.

"If you're running Oracle Linux and want support, you can purchase a support contract from us (and it's significantly cheaper than support from Red Hat)," Oracle says.

Basic and "limited" support for Oracle Linux starts at $499 for a year on one system and goes up to $2,299. On a three-year programme, Oracle starts at $1,497 and tops out at $6,897.

According to Oracle the CentOS switch code "[i]s not some gimmick to get you running Oracle Linux so that you buy support from us."

That's not how CentOS users are seeing it on this forum for Hacker News, though.

Forum member Spearchucker fires back:

That 'support' word, right there, is the thing that makes me stay as far from Oracle as I can. It's like "Dude, here's the software. Have it, it's cheap/free." When things go wrong you get stung for exorbitant support/consulting fees, because, hey, you're tied in. With nowhere to go.

The fact it's Oracle behind Oracle Linux is the biggest sticking point. The CentOS penguins either don't trust Oracle or hate it for throwing its weight around in the open source community, hurting their friends and other projects, and trying to control open source - the Hudson and OpenSolaris projects.

Others take issue with the fact Oracle is really RHEL without the branding. Davidmr says: "You say that they've produced something useful; can you say a little more about what Oracle has specifically produced with respect to Oracle Linux? My strong impression is that they've taken 99.9% Red Hat's hard work, dumped their own 0.1% on top (OCFS2, some IB enhancements, etc), slapped a big price tag on it and then exclaim, 'look what we made!'"

No amount of Dtrace or speedy updates seems capable of erasing the memory of Oracle's heavy-handed handling of projects such as Hudson and OpenSolaris. Oracle's Android suit also seems to be at the back of open-sourcers' minds.

Notatoad says: "I'm not going to build a business on top of a product that might be used next week as a tool to sue me or my friends. This was the only deciding factor when I chose Postgres over MySqL earlier this year for my company.

"If you want to market to linux nerds, you need to change the perception of the company, because that's what matters most right now. Stop being evil, and then we'll give your products a chance."

Runjake sums up the feeling: "The problem with Oracle Linux is that it's from Oracle. And I just don't trust them at all. I know I can revert back to CentOS or SL or whatever, but that's a pain. Trust is the problem."

Whenever The Reg runs into Oracle people at Linux and open-source events, they complain that Oracle doesn't get the credit or attention it deserves for its work on Linux. Here is something they can take back to Redwood shores.

Thanks to Reg reader Keith, who alerted us to this story. ®