...major server makers and Linux suppliers.
Technically, Xen and OpenVZ are complementary; the first lets several independent operating systems run on a server, while the second subdivides a single instance. But in practice, their similar goals means there is some overlap.
Indeed, Novell is focusing just on Xen and has no current plans to use either OpenVZ or Vserver, according to a company spokesman.
"Virtualisation is the number one customer request for our next generation of Linux enterprise products. We're delivering the Xen 3.0 hypervisor as part of SuSE Linux Enterprise Server 10 this year," he says.
"We're constantly researching the virtualisation space and will pick other technologies if they meet the needs we've identified," he adds. "At this time, neither of these projects [OpenVZ or Vserver] has met our criteria."
But SWsoft hopes that OpenVZ will pick up backing from major distributors of Linux versions, whose products typically use kernels with modifications not in the mainline kernel Linus Torvalds releases.
"Our main goal is to be included in SuSE Linux and Red Hat Enterprise Linux," Korotaev says.
Red Hat is a significant ally. "It's interesting to us. We're working with them so they can get their software upstream and into Fedora," a spokeswoman for the Linux distributor, says. And the company is helping with mainline kernel acceptance as well, she says. "There are some kernel changes that need to be made to implement resource management."
But getting into the kernel will be a challenge. For one thing, Andrew Morton, a top deputy to Torvalds, told ZDNet UK sister site CNET News.com he hasn't looked at OpenVZ or Vserver.
Korotaev knows there is work to be done. "It's a long process. We need to have a lot of conversations with Andrew Morton and Linus Torvalds," he says. "I'm not sure it will be easy, because the concept of virtual private servers is quite intrusive to the Linux kernel. The main problem is making clean code that will community will accept."
Becoming open source
OpenVZ has always been governed by the GPL, but it didn't become a full-fledged open source project until last September. Outside help with the software can help steer it in directions customers want and help programmers find bugs faster, Korotaev says.
And unsurprisingly, there's a profit motive involved as well. "We hope to drive more attention to Virtuozzo," Korotaev says. Virtuozzo adds tools for tasks such as managing virtual private servers remotely, backing them up, creating them or moving them from one computer to another without shutting them down.
In the past, although source code was available to those who requested it, as required by the GPL, SWsoft was reluctant to share, Korotaev says.
"There were some ideas about competitors, such as Vserver. We didn't want them to access our code easily," Korotaev says. "Sure, they could get [source code] if they bought Virtuozzo. But when our technology was only started, it was important that our ideas wouldn't appear in another project."
The approach meant SWsoft staff "basically were violating the GPL by not providing the source to their kernel modifications to their customers," says Vserver project leader Herbert Poetzl.
However, Poetzl, who says he declined an offer from SWsoft to maintain OpenVZ, welcomed the Linux push.
"I'm actually very happy that they started this project," Poetzl says. "The competition leads to improvements on both sides, which in turn benefits the customer."
