Why FreeBSD is used as the server operating system

The reason why FreeBSD is used as the server operating system-Linux Enterprise Application-Linux server application information. The following is a detailed description. Since 2001, when DragonFly BSD, the last major branch, was released, FreeBSD, OpenBSD, NetBSD, and Mac OS X represent a new wave of innovation in the UNIX world. All these operating system branches comply with POSIX and provide a similar command line interface for their users, in addition, kernel and system libraries that make the programming mode and Application Usage features as similar as possible are used.

In terms of provisions, BSD cannot be regarded as a UNIX system. However, the idea that the branches of BSD represent open-source UNIX has been widely accepted. It is surprising that no free operating system running on a PC or Mac can be named in 1980s and early 1990s. UNIX exists on the mainframe and Scalable Processor Architecture (Scalable Processor Architecture, or iSCSI. Major Private UNIX companies have divided the commercial UNIX Market.

The initial BSD operating system is ipvbsd.

The two major events that occurred in 1993 always changed UNIX: the establishment of the NetBSD team and the re-prevalence of the javasbsd patch tool. A decade ago, bsd unix developers recruited again from all levels of staff at the University of California, Berkeley, and PhD students, most of the funds come from Defense Advanced Research Projects Agency and DARPA, but the form of funds raised has ended. The objective BSD project was established in 1985 as an attempt to run bsd unix on Intel chips. Before December 31, 1989, the project had never released its first version. For many reasons, the project eventually became a reference operating system claimed by Dr. Dobb's Journal in July 1992. For ipvbsd 0.1, 250,000 downloads are known.

Javasbsd mainly improves the concept of UNIX dependency based on the views of Bill and Lynne Jolitz. Their original intention was to develop a free operating system. However, it turns out that it is not within their power to support a complete operating system. The system eventually lost to Linux, which was built by a program team composed of unknown Finnish students.

FreeBSD history

Another group that initially decided to build bsd unix on an Intel chip was established in 1993. Based on the previous work of Bill Jolitz, the team launched FreeBSD December 1993 in 1.0. In early 1997, project leader Jordan Hubbard promoted the development of the project and managed infrastructure and 200 developers. FreeBSD is expected to launch version 6.0 by the end of this year. This version will become the most important version of all free UNIX systems. FreeBSD does not clone UNIX, although it works in a UNIX-like way, and both its kernel and system APIs comply with UNIX standards.

FreeBSD is not just applicable to Intel-/AMD systems as before. It can also run on the SPARC64 computer and has a long running history in the Alpha architecture. If a BSD user is interested in running Mac OS x chips, he can switch to Darwin OS, the open source core of Mac OS x. Darwin OS depends on most FreeBSD V5.0 and its subsequent products. Of course, NetBSD has been running on all Mac architectures since 1995.

What are functions that FreeBSD does not have while Linux does?

　　

FreeBSD is an operating system, not just a kernel. However, this statement does not mean that it is roughly the same as the previous statement, because the kernel name is quite random. In a UNIX environment, it means that after the boot process is completed, users cannot access certain libraries and executable files. The kernel manages the hardware of applications. However, many UNIX operating systems currently provide a role for user-level threads to manage kernel resources. You can safely assume that anything that users cannot access during the running time is part of the kernel. This does not mean that the user cannot influence the behavior of the kernel. For example, some utilities can report and adjust memory management, and these tools clearly indicate that they are used by users. These utilities communicate through system APIs, which are not part of the kernel, but are clearly part of the operating system. Of course, FreeBSD includes all of these tools and many other utilities and applications used to handle network and hardware features.

If you have a complete Linux kernel download and FreeBSD download, you will understand that many of the download content is the same. That is to say, they all have IP stack, memory management routines, file system implementation, and so on. The hierarchical structure of the file system has a similar origin, and most command line applications have the same name and Similar command line semantics. Of course, the actual implementation is somewhat different, but you can still see that both systems have similar conceptual sources. The main difference in architecture is that FreeBSD reads files from the so-called buffer cache in a different way from the way Linux writes files to it. Strictly speaking, this cache is not even an entity that exists independently of the virtual memory. Linux always automatically manages the buffer cache size, but its memory management routines work in different ways than FreeBSD.

Port and File System

FreeBSD will work immediately after installation. The reason is that the FreeBSD system uses the FreeBSD installer to install a working system, also known as sysinstall, and uses a data packet management system with a clean UNIX origin. However, FreeBSD does more than this: Packet management has been thoroughly improved; binary and source data packets are no longer subject to unstable packet management systems, which is a common problem in Linux distribution. FreeBSD uses the Ports system to integrate packet management and Internet range updates, allowing you to solve source download and compilation problems in a process. Some may argue that Debian has similar advantages, but do not forget that Debian is an operating system and does not rely mainly on the Linux kernel. Using the Hurd and NetBSD kernels can also work properly, provided that the Debian project does not forget to update data packets.

When it comes to FreeBSD File systems, it will also be reminiscent of its bsd unix: it is dominated by the names of Fast File System (FFS) and UNIX File System (UFS. More often, users interact with the FFS part of the file system, which controls access to files and directories. Version 2003 of the UFS system, released in 2nd, sets File System Restrictions and the basic data structure for organizing access to the original disk. UFS and FFS can also be used in NetBSD and OpenBSD. Currently, more famous log File systems on Linux are unavailable on FreeBSD. These systems include Reiser File System (Reiser FS) and Journaling File System (JFS ), this is mainly for security considerations. UFS has other advantages such as stability and scalability, because its behavior and performance depend on more than 20 years of research.

Security and compatibility

Other advantages may affect your selection, so that you take FreeBSD more seriously. Although code-level security like OpenBSD is not provided, FreeBSD provides a powerful ready-to-use security mechanism. Since FreeBSD V5.0, you can add strict access control and security policies (which have sources in the TrustedBSD project supported by DARPA ). FreeBSD supports the access control list (ACL) and Mandatory Access Control (MAC) modules. Its system administrators and managers can naturally access the MAC module, but it allows small businesses to run networks using security standards that are strictly applied to systems subsets exposed to the outside world. UFS V2 provides excellent ACL support through extended attributes. If you need ACL, you must configure UFS V1 separately.

If you use Linux, you may see applications that can be used for SuSE Linux and Mac OS X, but there is no separate source file or binary file for FreeBSD. FreeBSD can run the Linux binary compatibility module. You must enable it during installation or from the command line. At the same time, Linux runtime libraries may be required, but you can add them from the Ports set.

Of course, FreeBSD runs all major desktop shell programs based on X Window System, such as KDE Desktop and GNU Network Object Model Environment (GNOME) Desktop. FreeBSD was previously the UNIX Version selected by a desktop user. It was not changed until FreeBSD-based OS X appeared. When configured as a server or client, it still provides good operations for UNIX users and does not require other certificates.

FreeBSD-derived product

Like most operating systems with a long history, FreeBSD also produces many derivatives. The FreeBSD system can be started from DC without compiling and producing CD. This work has been completed by a well-developed Free System Burned in Economy (FreeSBIE) V1.1 LiveCD System, which is based on FreeBSD V5.3. If it is risky to allocate some hard disks and write data to the master boot record (MBR), test FreeBSD first.

DragonFly BSD is based on FreeBSD V4.x, but it is not intended for common users. On the homepage of its website, it mentions a clustered file system that protects the Internet-which seems to be of little relevance to users who use UNIX for the first time. Founded by FreeBSD virtual memory experts, DragonFly BSD attempts to implement a completely new method to manage a large number of secure file systems and memory.

About documentation

Operating system documents that come with UNIX systems are generally not mentioned, because such documents are not as easy to read as their spontaneous fun and usefulness. FreeBSD document is an exception to this rule because it does not focus much on legacy manual pages, UNIX document styles, or copies of organizations.

FreeBSD documents appear on the Internet and on paper in a concise form of books, and each aspect of each system and system is presented in a pleasant and reasonable form. This does not imply that you must be familiar with UNIX systems. In fact, this is very helpful for new UNIX users. It not only explains simple FreeBSD installation, but also clearly introduces the reasons for FreeBSD kernel compilation or security protection. Interestingly, you can see the content ignored in the FreeBSD document, such as Perl and Apache, And the content contained in this document, such as Berkeley Internet Name Daemon (BIND) and the Storage Manager Vinum specific to FreeBSD. Vinum manages virtual disk drives and can replicate RAID 0, RAID 1, and RAID 5.

Administrator Operating System

FreeBSD can be described as a network administrator's operating system: it is fast, supports SMP, and can be integrated with a large number of network tools. In addition, FreeBSD performs smoother and faster when running Office applications and email clients and databases on a laptop. Its installation routine for Microsoft®Windows®Advanced users are very simple. It also provides many functions for Linux users because it provides binary compatibility mode and does not change the proprietary Linux operating system. FreeBSD is highly scalable and can be run as an application written in Linux or BSD. However, do not consider FreeBSD as a omnipotent "Swiss Army Knife" in the free operating system: it neither has the security of OpenBSD nor has scalability of the future Open Solaris version. However, it can rival any operating system running on an Intel chip-commercial or free-and in many ways, compared to its closest competitor, it provides a more stable and scalable platform.