The fourth major milestone release in 2013 of the open-source Linux kernel is now out, providing users with improved performance and new capabilities, including support for the Lustre filesystem.
Among the big new items included in the Linux 3.11 kernel is the initial support for the Lustre filesystem. Lustre is a widely deployed high-performance computing (HPC) filesystem used by many of the world's top supercomputers. It got its start with Cluster File Systems, which was acquired by Sun Microsystems in 2007. Sun became part of Oracle in 2010, and Lustre languished somewhat. In February of 2013, Xyratex acquired the name "Lustre" and its associated intellectual property assets from Oracle.
Linux 3.11 also introduces support for the new Network File System (NFS) 4.2 standard, which is currently in development at the Internet Engineering Task Force (IETF). Among the new features that NFS 4.2 introduces is the ability to do a server-side copy.
"A traditional file copy from one server to another results in the data being put on the network twice—source to client and then client to destination," the NFS 4.2 draft standard states. "New operations are introduced to allow the client to authorize the two servers to interact directly."
Additionally, Linux 3.11's new NFS 4.2 integration will support labeled NFS, which enables the use of security labels to control access.
"While both clients and servers can employ Mandatory Access Control (MAC) security models to enforce data access, there has been no protocol support to allow full interoperability," the NFS 4.2 draft standard states. "A new file object attribute, sec_label allows for the server to store and enforce MAC labels."
Linux 3.11 is also set to get a performance boost by way of the new Zswap lightweight compressed cache for swap pages in system memory. According to the Linux 3.11 kernel documentation on Zswap, the new feature takes memory pages that are in the process of being swapped out of system memory and attempts to compress them into a dynamically allocated RAM-based memory pool.
"Zswap basically trades CPU cycles for potentially reduced swap I/O (Input/Output)," the Zswap documentation states. "This trade-off can also result in a significant performance improvement if reads from the compressed cache are faster than reads from a swap device."
The ARM architecture has become increasingly important to Linux. The Linux 3.7 release in December of 2012 consolidated support for multiple ARM architectures into the Linux kernel.
In Linux 3.11, support for the use of memory "huge pages" on both 32-bit and 64-bit is now supported. Huge pages refers to memory "page" allocations of 2MB, as opposed to the default 4KB memory pages.
Linux for Workgroups
The Linux 3.11 kernel release has been named "Linux for Workgroups" by Linux creator Linus Torvalds. The name is, of course, a reference to the infamous Microsoft 3.11 Windows for Workgroups release from 1993. The name change for the kernel is the first since the Linux 3.8 release in February of this year that Torvalds had affectionately named the "Unicycling Gorilla."
Sean Michael Kerner is a senior editor at eWEEK and InternetNews.com. Follow him on Twitter @TechJournalist.