《计算机专业英语》谢希仁第二版第5章讲义.ppt

New Words Expressions: reliability n. 可靠性 audit v. 审计，查核 security-related adj. 与安全相关的 intrusion n. 入侵 5.2 FreeBSD vs. Linux vs. Windows 2000 5.2 FreeBSD vs. Linux vs. Windows 2000 Reliability FreeBSD(Berkeley Software Distribution)is extremely robust. There are numerous testimonials of active servers with uptimes measured in years. The new Soft Updates file system optimizes disk I/O for high performance, yet still ensures reliability for transaction based applications, such as databases. 可靠性 FreeBSD系统非常健壮，有众多的常年稳定运行的服务器可以证明这一点。 新的软件升级使文件系统优化了磁盘I/O以获得更高的性能，同时也保证了像数据库这样的基于事务的应用软件更加稳定运行。 5.2 FreeBSD vs. Linux vs. Windows 2000 Linux is well known for its reliability. Servers often stay up for years. However, disk I/O is non-synchronous by default, which is less reliable for transaction based operations, and can produce a corrupted file system after a system crash or power failure. But for the average user, Linux is a very dependable OS. Linux 系统也是以稳定而著称，安装Linux系统的服务器可以长年稳定工作。但是Linux系统的磁盘I/O是非同步的，这降低了基于事务的操作的稳定性，在系统出错或者电源失效的情况下会导致文件系统的错误，但是对一般的用户而言，Linux系统已经非常可靠了。 5.2 FreeBSD vs. Linux vs. Windows 2000 All Windows users are familiar with the Blue Screen of Death. Poor reliability is one of the major drawbacks of Windows. Some of the major issues have been fixed in Windows 2000, but code bloat has introduced many more reliability problems. Windows 2000 uses a lot of system resources and it is very difficult to keep the system up for more than a couple of months without it reverting to a crawl as memory gets corrupted and file systems fragmented. 所有的Window用户都习惯了蓝屏错误，可靠性差是Windows 系统的主要缺陷。Windows 2000系统修正了部分主要缺陷，但是由于系统代码非常庞大，导致存在很多的稳定性隐患。Windows 2000 系统使用了大量的系统资源，而且系统很难持续运行几个月，原因是由于文件系统产生了大量的碎片和内存分配的混乱。 5.2 FreeBSD vs. Linux vs. Windows 2000 Performance FreeBSD is the system of choice for high performance network applications. FreeBSD will outperform other systems when running on equivalent hardware. The largest and busiest public server on the Internet, at /