rPath Creates Malleable, Serviceable Linux Distribution

Published: March 14, 2006

by Timothy Prickett Morgan

The great thing about open source software is that it is so malleable. In the Linux space, you can grab a kernel, and bunch of systems and applications software, and throw it all together and make your own personal distribution. But, alas, if you do that, then you have to support it yourself. Your own knowledge of coding and projects has to be equivalent to that of a commercial Linux distributor, and you have to have time to keep your own system up to date. And if you have a problem, you have to rely on the kindness of colleagues and strangers.

This is simply not a palatable or practical option for enterprise computing, which is why the commercial Linux distributors emerged with business-class release schedules for the Linux stack and the expected installation and technical support that enterprises expect. But, as good as these commercial implementations of Linux are, they do not fulfill the true malleable nature that open source software has, which is one of its great benefits compared to proprietary and closed source software. Imagine, then, if you could have the best of both worlds. Imagine if you could build your own Linux distribution, all the way up to the systems and applications software stack, and punish someone else with grabbing the current source code from the open source projects, testing it, and integrating it with your solution.

This is what the founders of rPath have imagined, and what its rPath Linux and rBuilder tool do.

rPath was founded last year and is headquartered in Raleigh, North Carolina, right down the road from commercial Linux distributor Red Hat, and has Erik Troan, the creator of Red Hat's RPM, or Red Hat Package Manager, as one of its founders. RPM, which now has a recursive acronym (RPM Package Manager) because this a joke that nerds just can't get enough of, has been adopted by various Linuxes, some Unixes, and even NetWare as the means for installing, updating, and removing system and application software from an operating system. Troan knows a thing or two about Linux, since he used to be chief technology officer and lead engineer on Red Hat's Linux implementation. Billy Marshall, rPath's other founder, is the company's chief executive officer and used to be vice president of sales in North America for Red Hat. Marshall is credited to coming up with the idea of the Red Hat Network, the support mechanism for that company's commercial Linux implementations for desktops, workstations, and servers. rPath has a lot Red Hat alums staffing its engineering centers. Michael Johnson, who founded the Fedora project and used to manage the Red Hat Linux kernel team, is a founding engineer at rPath, and so is Matt Wilson, the former head of Red Hat operating system engineering who created the Anaconda installer for Fedora. Cristian Grafton, rPath's software architect, was the chief architect of the Red Hat Network software; Nathan Thomas, who is director of field engineering, had the same post at Red Hat, and Marty Wesley, director of product marketing, had that job at Red Hat as well as being manager of the Red Hat Enterprise Linux line.

All of this begs the question: Who is working at Red Hat? But anyway.

rPath is trying to bring to the market the concept of a software appliance built on a customizable repository of Linux kernels and several hundred open source software components. Essentially, you deploy rPath Linux, picking the kernel of your choice, which rPath builds from the kernel.org Linux kernel development site. Then you pick any number 700 programs in the repository--which are drawn from the 265 key open source projects--and rPath Builder, the repository tool, worries about all of the interdependencies between the kernel and your software stack. You hit a button and rPath kicks out a gold image of your stack. If you need to change kernels, or add something to the software appliance, you do it from the repository and it kicks out a new gold image. In effect, you become your own personal Red Hat, Novell, Mandriva, or Turbolinux, and you don't have to deal with source code and compilers.

"We think Linux and open source should be a distributed model," explains Marshall. "There are parts of the stack where software companies are the best determiners of the components, and we give them the tools to do it. In essence, we make the operating system disappear."

With the rPath Linux and rBuilder tool, the customer--whether it is an enterprise customer building their own application platforms or a software developer that sells applications to such customers--are in control of the software stack, not another software provider or the open source projects. The way it works now, software vendors and open source projects set the pace for when a given application rollout can occur. If the operating system or a key feature such as a Web application server or database is delayed or out of synch in some way, then the whole project is slowed to the speed of the delivery of the most delayed component. rPath wants to do away with this approach, allowing independent software vendors to develop along their own schedules using the piece parts they want, thereby avoiding having to align with other company's schedules. Then, there is the whole re-certification nightmare each time a component changes. rPath gets around this problem by only putting the components in that you want--nothing else. If you had 15 components when you first set up the appliance, if you update one or more of those components with new code from the open source projects (extracted from the rBuilder repository, not from the Web), then you will only have 15 components when the upgrade is done. Other installers often add extra stuff in that is not necessary, but simply makes dependencies easier to resolve.

"You can think of us as a super-Yast, driven by a massive repository," says Marshall, referring to the installer at the heart of SUSE Linux. "We only have a few kernels right now, and we are not going to do fifty different kernels. But we are allowing mass customization on the kernels we do have, and we get customers away from the matrix of pain."

rPath put out a public beta of its rBuilder tool last October, launched the company in January, and put the tool in production a few weeks ago. The company has more than 22 employees (and, as you can see, a very large number of Red Hat ex-pats) and hopes to double this year, and has received $6.4 million in funding from two venture capitalists, North Bridge Venture Partners and General Catalyst. rPath Linux runs on 32-bit X86 and 64-bit X64 platforms and can be run inside a VMware or Xen virtual machine partitions as well as on bare hardware. rPath Linux is getting beefed up Java support, although it does include Apache Struts and Tomcat already, says Marshall, and the company has built an appliance to run the SugarCRM customer relationship management suite.

rPath is not a toy Linux, and therefore it is not cheap. To get access to the rBuilder repository and five copies of rPath Linux for developers costs $5,000, and it costs $15,000 per year per developer to keep the repository updated. If you are an ISV creating appliances that you sell to customers--which is the intended market for this product--then it costs $100 per server socket per year for support and maintenance for each box you sell with your software appliance on top of it. This is a reasonable fee, and even the development stack is priced competitively with other commercial development tools.