Bucking standard conventions in software versioning, Linux Torvalds has designated the new release of the Linux operating system kernel, posted Friday, as version 3.0, even while maintaining that the release is only a routine update.
"Sure, we have the usual two thirds driver changes, and a lot of random fixes, but the point is that 3.0 is *just* about renumbering ... No breakage, no special scary new features, nothing at all like that," Torvalds wrote on the Linux Kernel mailing list.
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The new kernel was almost released on July 19, but the last-minute discovery of a subtle bug, and testing of a patch for it, delayed the release.
For the past eight years, the volunteer developers behind Linux have been laboring on version 2.6. This new release was bumped up to version 3.0 in honor of Linux's 20th anniversary -- which takes place this year -- as well as to streamline the increasingly cumbersome version numbering -- the previous stable version of Linux kernel was 126.96.36.199.
"It really is just another release along the lines of those we have been making since the beginning 2.6 days," said Jonathan Corbet, a kernel contributor as well as the editor of kernel watchdog site Linux Weekly News. "People read a lot into version numbers, but that really shouldn't be done here."
"The problem was that the numbers were just getting too high, and the '2.6' prefix didn't mean anything anymore," Corbet added. The developers agreed to jump to 2.7 should they need to fix a problem that would take longer than the 8 to 12 week release cycle, but no such problem ever emerged, and the minor updates spawned ever-more unweldy version numbers.
As an example, under the old numbering scheme, this version of the kernel would be 2.6.40, and the first update would be 188.8.131.52. In the new scheme, the first bug fix update will be 3.0.1. (For compatibility with older programs, the kernel will identify itself as 3.0.0 instead of 3.0).
This new release features improvements in virtualization and file system support, in addition to the usual round of bug fixes and performance tuning.
Four years in the making, this version of the kernel is the first able to grant Xen hypervisor Dom0 (Domain 0) privileges. By having Dom0 privileges, the Xen hypervisor can run as the primary, or most privileged, layer for the computer. It can then parcel out access to other guest operating systems, which should speed performance of these guests. Previous versions of Xen offered this capability only by applying patches to the kernel.
The Xen update has been a long time in coming, Corbet said.