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Is There Perfection in The Linux Kernel?

In a perfect world, you could compile a brand-new Linux kernel without the need for much configuration and without error.

According to Linus Torvalds, the new 2.6.19 Linux kernel is such an entity.

"It's one of those rare "perfect" kernels," Torvalds wrote in a Linux kernel mailing list posting announcing the new kernel. "So if it doesn't happen to compile with your config (or it does compile, but then does unspeakable acts of perversion with your pet dachshund), you can rest easy knowing that it's all your own d*mn fault, and you should just fix your evil ways."

The 2.6.19 kernel is the fifth and likely final main Linux kernel point release for this year. Among the most noteworthy aspects of the new kernel are three new filesystem additions.

Linux supports a number of filesystems but arguably the most widely used and deployed of the bunch is the ext3, which first appeared in the 2.4.15 kernel in November of 2001. The next evolution, ext4, has support for storage volumes of up to 1024 petabytes, which shatters the 32 terabytes that ext3 maxes out at.

The new ext4 will still mount ext3 filesystems, which is consistent with how ext3 supported its legacy ext2 forebears.

It's not certain yet, but Red Hat's Fedora Core 7 might include ext4 when it is released early next year. Red Hat developer Dave Jones told Fedora Core mailing list members that ext4 will be in Fedora's rawhide development tree but whether it makes it into FC7 depends on how it works out.

"It may not be as supported throughout the distro as ext2/3 though (ie, you may not be able to install to it), depending again on how quickly it matures," Jones wrote.

Red Hat itself has a bit of a hand in filesystem additions for Linux 2.6.19. A Red Hat-developed clustering filesystem called GFS2 is part of the new kernel.

A clustered file system extends a filesystem for high availability failover clustered environments.

GFS (Global File System) is a technology first developed by Sistina Software. Red Hat acquired Sistina in December 2003. Some six months after the acquisition Red Hat rolled out its first Red Hat-branded version of GFS.

Red Hat's GFS is actually the second clustered filesystem supported by Linux. The first one is Oracle's OCFS2 cluster filesystem, which was first included in the 2.6.16 kernel eight months ago.

Version 2.6.19 also includes a new encrypted filesystem called eCryptfs. According to the project's eCryptfs Sourceforge.net description, cryptographic metadata is stored in the header of each file written with eCryptfs. The encrypted file is de-cryptable with the proper key.