Five months after unveiling the FreeBSD Release 5.0 operating system, The FreeBSD Foundation followed up with the release of FreeBSD 5.1 Monday.
The Foundation said FreeBSD 5.1 provides additional stability, reliability and performance to the FreeBSD 5.x branch, while also delivering a number of the infrastructure improvements laid out on the 5.x road map.
Among the new features are:
- Experimental threading libraries that provide 1:1 and M:N kernel support for multithreaded applications, improving performance and allowing applications to take advantage of multiple CPUs
- Expanded hardware support for USB 2.0, IBM/Adaptec ServeRAID controllers, USB Ethernet adapters, and Promise and Intel Serial ATA controllers
- Enhanced "jail" management, which allows one server to provide many different virtual machines
- Support for Physical Address Extensions, allowing the use of up to 64GB of RAM on supported x86 platforms
- Experimental support for AMD's Opteron 64-bit platform
The improvements build on the features of FreeBSD 5.0, launched in January, which for the first time added support for Sun's Sparc64 and Intel's IA64 platforms. The 5.0 release also included fine-grained locking in the kernel, providing multiple threads to execute in the kernel at the same time. Additionally, 5.0 introduced the GEOM storage framework, an infrastructure in which "classes" can perform transformations on disk I/O requests on their path from the upper kernel to the device drivers and back. This allows the operating system to support block encryption schemes.
The Foundation said FreeBSD 5.1 is ready for deployment as a desktop or server system for those interested in the latest FreeBSD technology, but its mature 4.x release branch is still preferred for those planning critical enterprise deployments. FreeBSD 4.8 was released in March, and 4.9 is forthcoming.
FreeBSD is patterned after the BSD (Berkeley Software Design) operating system, which split off from the Unix operating in the early 1990s. Until that point, academics around the world had helped AT&T work on the Unix code, and Berkeley Unix hackers added Internet capability to the code base around 1980. By 1990, the relationship between AT&T's Unix Systems Laboratories (USL) and Berkeley had soured, leading to a three year lawsuit with a settlement that severed Berkeley's version of the Unix source, BSD, from AT&T.