85091d3db7
Submitted by: Emily Boyd (emilyboyd at emilyboyd dot com) Sponsored by: Google Summer of Code 2005
166 lines
7.6 KiB
Text
166 lines
7.6 KiB
Text
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" [
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<!ENTITY date "$FreeBSD: www/en/features.sgml,v 1.26 2005/07/16 06:26:38 rushani Exp $">
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<!ENTITY title "About FreeBSD's Technological Advances">
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<!ENTITY % navincludes SYSTEM "includes.navabout.sgml"> %navincludes;
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<!ENTITY % includes SYSTEM "includes.sgml"> %includes;
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]>
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<html>
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&header;
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<h1>FreeBSD offers many advanced features.</h1>
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<p>No matter what the application, you want your system's resources
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performing at their full potential. FreeBSD's advanced features
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enable you to do just that.</p>
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<h2>A complete operating system based on 4.4BSD.</h2>
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<p>FreeBSD's distinguished roots derive from the latest <b>BSD</b>
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software releases from the Computer Systems Research Group at the
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University of California, Berkeley. The book <i>The Design and
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Implementation of 4.4BSD Operating System</i>, written by the 4.4BSD
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system architects, thus describes much of FreeBSD's core functionality
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in detail.</p>
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<p>Drawing on the skills and experience of a diverse and world-wide
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group of volunteer developers, the FreeBSD Project has worked to
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extend the feature set of the 4.4BSD operating system in many ways,
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striving constantly to make each new release of the OS more stable,
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faster and containing new functionality driven by user requests.</p>
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<h2>FreeBSD provides higher performance,
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greater compatibility with other operating systems and less system
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administration.</h2>
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<p>FreeBSD's developers attacked some of the more difficult problems in
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operating systems design to give you these advanced features:</p>
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<ul>
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<li><b>A merged virtual memory and filesystem buffer cache</b>
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continuously tunes the amount of memory used for programs and the
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disk cache. As a result, programs receive both excellent memory
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management and high performance disk access, and the system
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administrator is freed from the task of tuning cache sizes.</li>
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<li><b>Compatibility modules</b> enable programs for other operating
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systems to run on FreeBSD, including programs for Linux, SCO UNIX,
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and System V Release 4.</li>
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<li><b>Soft Updates</b> allows improved filesystem
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performance without sacrificing safety and reliability.
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It analyzes meta-data filesystem operations to avoid having
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to perform all of those operations synchronously.
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Instead, it maintains internal state about pending meta-data
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operations and uses this information to cache meta-data,
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rewrite meta-data operations to combine subsequent
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operations on the same files, and reorder meta-data
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operations so that they may be processed more efficiently.
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Features such as background filesystem checking and
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file system snapshots are built on the consistency
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and performance foundations of soft updates.</li>
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<li><b>File system snapshots</b>, permitting administrators to take
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atomic file system snapshots for backup purposes using the free
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space in the file system, as well as facilitating <b>background
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fsck</b>, which allows the system to reach multiuser mode without
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waiting on file system cleanup operations following power outages.
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</li>
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<li>Support for <b>IP Security (IPsec)</b> allows improved security in
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networks, and support for the next-generation Internet Protocol,
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IPv6. The FreeBSD IPsec implementation includes support for a
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broad range of <b>accelerated crypto hardware</b>.</li>
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<li><b>Out of the box support for IPv6</b> via the KAME IPv6 stack
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allows FreeBSD to be seamlessly integrated into next generation
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networking environments. FreeBSD even ships with many applications
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extended to support IPv6!</li>
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<li><b>Multi-threaded SMP architecture</b> capable of executing the
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kernel in parallel on multiple processors, and with <b>kernel
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preemption</b>, allowing high priority kernel tasks to preempt
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other kernel activity, reducing latency. This includes a
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<b>multi-threaded network stack</b> and a <b>multi-threaded
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virtual memory subsystem</b>. With FreeBSD 6.x, support for a
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fully parallel VFS allows the UFS file system to run on multiple
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processors simultaneously, permitting load sharing of
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CPU-intensive I/O optimization.</li>
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<li><b>M:N application threading via pthreads</b> permitting threads
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to execute on multiple CPUs in a scaleable manner, mapping many user
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threads onto a small number of <b>Kernel Schedulable Entities</b>.
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By adopting the <b>Scheduler Activation</b> model, the threading
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approach can be adapted to the specific requirements of a broad
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range of applications.</li>
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<li><b>Netgraph pluggable network stack</b> allows developers to
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dynamically and easily extend the network stack through clean
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layered network abstractions. Netgraph nodes can implement a broad
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range of new network services, including encapsulation, tunneling,
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encryption, and performance adaptation. As a result, rapid
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prototyping and production deployment of enhanced network services
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can be performed far more easily and with fewer bugs.</li>
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<li><b>TrustedBSD MAC Framework extensible kernel security</b>,
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which allows developers to customize the operating system security
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model for specific environments, from creating hardening policies
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to deploying mandatory labeled confidentiality of integrity
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policies. Sample seucrity policies include <b>Multi-Level
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Security (MLS)</b>, and <b>Biba Integrity Protection</b>. Third
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party modules include <b>SEBSD</b>, a FLASK-based implementation
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of <b>Type Enforcement</b>.</li>
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<li><b>GEOM pluggable storage layer</b>, which permits new storage
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services to be quickly developed and cleanly integrated into the
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FreeBSD storage subsystem. GEOM provides a consistent and
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coherent model for discovering and layering storage services,
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making it possible to layer services such as RAID and volume
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management easily.</li>
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<li>FreeBSD's <b>GEOM-Based Disk Encryption (GBDE)</b>, provides
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strong cryptographic protection using the GEOM Framework, and can
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protect file systems, swap devices, and other use of storage
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media.</li>
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<li><b>Kernel Queues</b> allow programs to respond more efficiently
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to a variety of asynchronous events including file and socket IO,
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improving application and system performance.</li>
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<li><b>Accept Filters</b> allow connection-intensive applications,
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such as web servers, to cleanly push part of their functionality into
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the operating system kernel, improving performance.</li>
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</ul>
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<h2>FreeBSD provides many security features
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to protect networks and servers.</h2>
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<p>The FreeBSD developers are as concerned about security as they are
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about performance and stability. FreeBSD includes kernel support for
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<b>stateful IP firewalling</b>, as well as other services, such as
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<b>IP proxy gateways</b>, <b>access control lists</b>, <b>mandatory
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access control</b>, <b>jail-based virtual hosting</b>, and
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<b>cryptographically protected storage</b>. These features can be
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used to support highly secure hosting of mutually untrusting
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customers or consumers, the strong partitioning of network segments,
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and the construction of secure pipelines for information scrubbing
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and information flow control.</p>
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<p>FreeBSD also includes support for encryption software, secure
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shells, Kerberos authentication, "virtual servers" created using
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jails, chroot-ing services to restrict application access to the
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file system, Secure RPC facilities, and access lists for services
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that support TCP wrappers.</p>
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&footer;
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</body>
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</html>
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