Test Plan Charlie Unplugged: An Interview with David Boyes - page 4
Meet David Boyes
Were the early versions of Linux for S/390 easy to install and usable after you got them running?
We were almost always installing under VM. If you had the advantages of VM and the tools around VM, then yes, they were always easy to install if you were comfortable with installing an operating system under a virtual machine. It was no difference installing Linux than any other virtual operating system.
On bare metal, it was a pain in the butt. The designers were always testing under VM and they assumed that things on bare metal would work the same. That's not always the case, such as with shared control units.
The first Marist distro was always very easy. The latest SuSE version has some changes that make it a little harder to install. I'm not a big fan of graphical installers because when they break they break spectacularly, but maybe that's just because I'm an old timer.
What applications do you think make sense for L390? What are bad fits?
I'll give an answer for now, for the next three years, and for five years out.
Today, what we see Linux on S/390 being most useful for is as an infrastructure server running e-mail, DNS, and the traditional back-office environment. The open source tools are available today, and are vastly superior to some of the commercial tools for the same tasks. It's not uncommon to have a Linux-based [e-mail] environment with tens of thousands of users on one system. That's not something I'd want to try on Lotus Notes or Microsoft Exchange. That's a good use today, a profitable use, for Linux 390.
In three years, I see an expanded role of Linux on S/390, and specifically Linux under VM. Right now applications, database, and web servers are three separate pieces. What I see then is that those three pieces become three instances under VM. To roll these applications into a virtual server environment becomes very easy to manage.
The architecture of the applications won't change. You'll still see the three-tier design where you have the application service, the database, and the web front end. A lot of the I/O intensive tasks are something where in the 390 world the cost is much lower. Gigabit Ethernet is cheap, but in between virtual machines I'm getting eight gigabytes for free once I've got the infrastructure in place.
In the long term I think distributed systems will be re-centralized. For Beowulf to be an effective technique, the problem has to be partitionable into little pieces that don't interact much with each other. What we're really talking about is how to partition applications. We've had thirty years of performance tuning, chargeback accounting, etc., in the VM environment. I think you're starting to see that discussion in how people are interested in ASPs. Thirty years ago we called them a timesharing organization. You don't have the resources or skill sets to do the job yourself, so you rent the service from someone who does. This means accounting becomes more important.
In five years, I think you'll see a lot of people looking at this type of solution. Sun and HP will not sit still, but IBM has a thirty year jump. Been there, done that.
So you think this is the right direction for the future?
I think we can't afford not to go this way, because the floor space of discrete systems is reaching the point of diminishing return.
For things like personal productivity applications, I don't think that will fit into this environment much. I think you'll see more of the big applications here. People want control of a personal system. For things where there is a lot of interactivity and customization will stay on the desktop. A good model for this would be a personal computer running Linux, using X11 to run remote applications on the 390. You have the same interface for both. This also requires broad-based availability of high-speed communication, but I think that's happening in most areas.
It's going to be a cooperative effort between what's on your desktop and what runs remotely. What typically people buy PCs for today is probably going to stay on there.