2012 was another busy year for Linux kernel developers as the continuous pace of evolution accelerated further. In total, seven major Linux kernels were released during the year adding a long list of new features along the way.
Linux 3.7 debutedearlier this month, and was the final Linux kernel release of 2012.
Of note in the 3.7 release is the consolidation of ARM into a single target architecture. As well, the 3.7 kernel provides support for the VXLAN Software Defined Networking protocol.
The Linux 3.6 kernelwas released at the end of September. Of note in the 3.6 release is that the kernel gained the ability to suspend to both memory and disk simultaneously.
Overall though Linux creator Linus Torvalds dubbed the 3.6 release as one full of ‘solid progress’.
“There haven’t been any huge new architectures or filesystems — it’s all ‘solid progress,'” Torvalds wrote in his release announcement. “That may not sound all that exciting, but the devil is in the details, and there’s a lot of small fixes all over.”
Linux 3.5 was released in July. The Ext4 filesystem was the big winner in this release gaining metadata checksum capabilities to in improve filesystem integrity gap.
“As much as we wish our storage hardware was 100 percent reliable, it is still quite possible for data to be corrupted on disk, corrupted during transfer over a wire, or written to the wrong places,” the kernel.org wiki on metadata checksums explains. “To protect against this sort of non-hostile corruption, it is desirable to store checksums of metadata objects on the filesystem to prevent broken metadata from shredding the filesystem.”
Linux 3.4 was released in May. The Btrfs filesystem got the btfs-restore utility in this release, which can help to recover data from a filesystem that is not mountable.
KVM virtualization also got a big boost, expanding the the maximum number of virtual CPUs (vCPUs) that can be supported in Linux, from 64 all the way to 160.Linux 3.3
Linux 3.3 was released in March and is notable for at least one primary reason: the return of Android.
“Turns out I was wrong, we want these in the tree,” Linux kernel developer Greg Kroah-Hartman wrote in his code commit adding Android drivers back into the Linux mainline.
Linux 3.2 was the first kernel of 2012 and was released in early January. Linux 3.2 was another big release for the Ext4 filesystem, with filesystem blocks grow to up to 1 MB in size up from the traditional 4 KB.