2-网络基础-云计算简介

<p class="MsoNormal"><b><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">云计算的模式：</span><span lang="EN-US"><o:p></o:p></span></b></p> <p class="MsoNormal"><span lang="EN-US">IaaS ( Infrastructrue as a service )</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">：基础设施即服务</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span lang="EN-US">IaaS </span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是通过因特网，以服务的形式提供运算能力，存储设备、网络即其他基础设施。</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">常见的亚马逊的</span><span lang="EN-US">AWS</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">，</span><span lang="EN-US">Google</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">的</span><span lang="EN-US">GCE</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">、</span><span lang="EN-US">IBM</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">的</span><span lang="EN-US">BlueCloud</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">和阿里云计算等均是</span><span lang="EN-US">IaaS<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><span lang="EN-US">Infrastructure</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">：基础设施、公共建设、下部构造</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><span lang="EN-US">SaaS </span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">（</span><span lang="EN-US">software as aservice</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">）</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">软件即服务</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span lang="EN-US">SaaS </span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是把应用软件通过网络以服务形式提供给用户使用。</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span lang="EN-US">Google Docs</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">和</span><span lang="EN-US">Google apps</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是常见的</span><span lang="EN-US">SaaS</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">服务。</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><span lang="EN-US">PaaS </span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">（</span><span lang="EN-US">Platform as aservice</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">）</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">平台即服务</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span lang="EN-US">PaaS </span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">与</span><span lang="EN-US">IaaS</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">相似，也是通过互联网，以服务的形式提供运算能力、存储设备、网络等服务。但是</span><span lang="EN-US">PaaS</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">使用的只是一个应用程序，而不像</span><span lang="EN-US">IaaS</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是整个机器的虚拟镜像。</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">例如八百客的</span><span lang="EN-US">800app</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">等是典型应用。</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><b><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">云计算的优势：</span><span lang="EN-US"><o:p></o:p></span></b></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">更节约成本</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">可以简单方便的实现可扩展性</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">高性</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">可测试可用性</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">其实，云计算就是</span><span lang="EN-US">Linux</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">中的一个服务。</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">虚拟化技术是构建云计算基础架构不可或缺的关键技术，常见的虚拟化解决方案有：</span><span lang="EN-US">Xen</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">、</span><span lang="EN-US">KVM</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">、</span><span lang="EN-US">VMware<o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><span lang="EN-US">C/S  </span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">客户端</span><span lang="EN-US">/</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">服务器端</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US">B/S  </span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">浏览器</span><span lang="EN-US">/</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">服务器端</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><span lang="EN-US">B/S</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">服务器的压力远大于</span><span lang="EN-US">C/S</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">服务器，因为</span><span lang="EN-US">B/S</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">结构中的所有数据都要经过服务器的运算，但是随着计算技术的强大，</span><span lang="EN-US">B/S</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">架构会取代</span><span lang="EN-US">C/S</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">架构。</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><b><span lang="EN-US"> </span></b></p> <p class="MsoNormal"><b><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">网站架构简介：</span><span lang="EN-US"><o:p></o:p></span></b></p> <p class="MsoListParagraph" style="margin-left:28.5pt;text-indent:-18.0pt;mso-char-indent-count:0;mso-list:l0 level1 lfo1;"><!--[if !supportLists]--><span lang="EN-US">1.<span style="font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:7pt;line-height:normal;font-family:"Times New Roman";">      </span></span><!--[endif]--><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">架构绝不是一成不变的</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoListParagraph" style="margin-left:28.5pt;text-indent:-18.0pt;mso-char-indent-count:0;mso-list:l0 level1 lfo1;"><!--[if !supportLists]--><span lang="EN-US">2.<span style="font-variant-numeric:normal;font-variant-east-asian:normal;font-stretch:normal;font-size:7pt;line-height:normal;font-family:"Times New Roman";">      </span></span><!--[endif]--><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">架构的设计要考虑今后的扩容与升级</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">缓存（服务器）会大大缓解数据库的压力。</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US">MYSQL</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">优化的核心思想：<span style="color:red;">读写分离</span></span><span style="color:red;"> <span lang="EN-US"><o:p></o:p></span></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">设计大访问量的架构时，应当加入中间件</span><span lang="EN-US">——DB</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">连接池，这是一个较难的东西，没有人专门教，只能由架构师自己解决。那么什么是</span><span lang="EN-US">DB</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">连接池呢？</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US">    <o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;mso-char-indent-count:2.0;"><span lang="EN-US">DB</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">连接池就是一个专门管理数据库的中间件，它可以在服务调用前打开很多的数据库，在服务需要时直接调用，调用完毕后直接撤离，数据库的关闭由</span><span lang="EN-US">DB</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">连接池来完成，这就减轻了大量服务涌入数据库时打开关闭数据库的负担。</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="EN-US"> </span></p> <p class="MsoNormal"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">减少数据库的压力（减少数据库的使用）有如下方法：</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">一是</span> <span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">使用内容分发系统（</span><span lang="EN-US">CDN</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">）</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">二是</span> <span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">使用静态资源服务器</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">三是</span> <span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">使用缓存服务器</span><span lang="EN-US"><o:p></o:p></span></p> <p class="MsoNormal" style="text-indent:21.0pt;"><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">四是</span> <span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">使用</span><span lang="EN-US">DB</span><span style="font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">连接池</span></p>

• 基础笔记综合整理
• 2018-09-28
• 评论
•   1693 次浏览

1-计算机基础

计算机的组成：主要分为五个部分<br /> 　　控制器：整个计算机的中枢神经，对程序规定的控制信息进行解释，根据要求进行控制，调度程序、数据、地址、协调计算机各部分工作、内存以及外部设备的访问。<br /> 　　运算器：运算器的功能是对数据进行各种算术运算和逻辑运算，即对数据进行加工处理<br /> 　　存储器：存储器的功能是存储程序，数据和各种信号、命令等信息，并在需要时提供这些信息<br /> 　　输入设备：将程序、原始数据、文字、字符、控制命令或现场采集的数据等信息输入到计算机，常见的设备有鼠标、键盘等<br /> 　　输出设备：将计算机处理后的各种数据、符号、文字或者各种控制信号等输出，常见的输出设备有显示器、打印机等<br /> 　　CPU=控制器+运算器<br /> 　　主板=I/O总线，输入输出系统<br /> 　　存储器=内存+硬盘<br /> 　　I/O设备：键盘鼠标、扫描仪显示器等等<br /> <br /> BIOS：basic input/output system 基本输出输出系统<br /> CMOS 互补金属氧化物半导体存储器<br /> CMOS是主板上的一块可读写的芯片用于保存当前系统上的硬件配置信息和用户对某些参数的设定<br /> <br /> MBR（MASTER Boot Record） 主引导记录<br /> MBR分区表：最大支持2.1T的硬盘，最多支持四个主分区<br /> MBR的分区类型<br /> MBR主分区最多只能有四个<br /> 扩展分区最多只能有一个<br /> 主分区+扩展分区最多只能有四个<br /> 扩展分区不能写入数据，只能包含逻辑分区<br /> #不同分区对逻辑分区支持的数量个数不同，至少可以划分十个逻辑分区<br /> GPT全局唯一标识：支持更大容量的磁盘，理论上支持无限个分区<br /> 格式化：<br /> 格式化（高级格式化）又称为逻辑格式化，它是根据选定的文件系统在磁盘上的特定区域写入特定的数据，在分区中划分出一篇用于存放文件的分配表，目录表等用于文件系统管理的磁盘空间。<br /> <br /> FAT32最大支持4GB的单个文件，<br /> windows分区的步骤：分区、格式化（写入文件系统），分配盘符<br /> 各接口的速率：<br /> PCI 外接声卡、网卡 66MB/s<br /> IDE 光驱、老式硬盘 133MB/s<br /> SCSI 老式服务器接口 200MB/s<br /> SATA 硬盘接口 500MB/s<br /> PCIE 显卡 1000MB/s<br /> DDR 内存 3代<2400MB/s 4代>=2400MB/s<br /> Block块：linux下默认为4KB<br /> Inode（Index node）：索引号，每一行INode的大小为128Bytes，系统通过INode号来查找文件，INode中存放了每一个文件的INode号、文件对应的权限、时间戳、数据块位置<br /> <br /> 虚拟机的配置：<br /> 内存要求：linux在虚拟机中安装的内存不能小于628MB，否则会执行简易安装<br /> 虚拟机中的内存不能大于实际物理机的真是内存<br /> 虚拟机中的CPU核心数改变时，需要将虚拟化勾选上。<br /> <br /> 快照：保存虚拟机当前的状态<br /> <br /> 虚拟机中的网络<br /> <table class="MsoTableGrid" border="1" cellspacing="0" cellpadding="0" style="border-collapse:collapse;border:none;mso-border-alt:solid windowtext .5pt;mso-yfti-tbllook:1184;mso-padding-alt:0cm 5.4pt 0cm 5.4pt;"> <tbody><tr> <td width="138" valign="top" style="width:103.7pt;border:solid windowtext 1.0pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">连接方式</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border:solid windowtext 1.0pt;border-left:none;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是否连接本地</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border:solid windowtext 1.0pt;border-left:none;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是否连接局域网</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border:solid windowtext 1.0pt;border-left:none;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是否连接公网</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> </tr> <tr> <td width="138" valign="top" style="width:103.7pt;border:solid windowtext 1.0pt;border-top:none;mso-border-top-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;">VMnet0</span><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">桥接（真实网卡）</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border-top:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border-top:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border-top:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> </tr> <tr> <td width="138" valign="top" style="width:103.7pt;border:solid windowtext 1.0pt;border-top:none;mso-border-top-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;">VMnet1</span><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">仅主机</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border-top:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border-top:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">否</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border-top:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">否</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> </tr> <tr> <td width="138" valign="top" style="width:103.7pt;border:solid windowtext 1.0pt;border-top:none;mso-border-top-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;">VMnet8<o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border-top:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border-top:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">否</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> <td width="138" valign="top" style="width:103.7pt;border-top:none;border-left:none;border-bottom:solid windowtext 1.0pt;border-right:solid windowtext 1.0pt;mso-border-top-alt:solid windowtext .5pt;mso-border-left-alt:solid windowtext .5pt;mso-border-alt:solid windowtext .5pt;padding:0cm 5.4pt 0cm 5.4pt;"> <p class="MsoNormal" align="center" style="text-align:center;"><span style="font-size:8.0pt;mso-bidi-font-size:6.5pt;font-family:宋体;mso-ascii-font-family:calibri;mso-ascii-theme-font:minor-latin;mso-fareast-font-family:宋体;mso-fareast-theme-font:minor-fareast;mso-hansi-font-family:calibri;mso-hansi-theme-font:minor-latin;">是</span><span lang="EN-US" style="font-size:8.0pt;mso-bidi-font-size:6.5pt;"><o:p></o:p></span></p> </td> </tr> </tbody> </table> <br /> windows版本的分类：<br /> 个人版：xp、win7、win8、win10<br /> 企业版：service2003、service2008、service2012<br /> <br /> window安装步骤<br /> 1. 拔网线<br /> 2. 安装windows<br /> 3. 安装杀毒软件、防火墙<br /> 4. 插入网线，更新windows补丁、防火墙库、病毒库<br /> 5. 常用软件的安装<br /> 6. 对于服务器来说还要做一些常规的优化<br /> <br /> 防火墙的基本功能：过滤数据包<br /> 防火墙过滤的基本规则：<br /> IP地址<br /> MAC地址<br /> 端口（端口与协议相关）<br /> 协议<br /> 数据包内容（高级防火墙才拥有的功能）<br /> #防火墙具有一定防范木马的功能，因为一些木马的传播是通过固定的端口传播<br /> <br /> windows操作系统的安装方法：<br /> 1. 光盘、U盘（个人版安装方法）<br /> 2. 磁盘对拷安装：<br /> 先安装好一台主机作为母盘，将母盘装在其他主机的一号硬盘接口，空白盘放入其他接口<br /> windows：ghost（幽灵）<br /> linux：dd命令<br /> #ghost也可以拷贝linux操作系统，ghost操作的对象是硬盘，它不管其中的数据是什么样的，整块磁盘拷贝，不论其中有没有数据，母盘放到第一个硬盘接口，服务器一般是左起第一块，如果主从放反，则会清空母盘中的数据。<br /> 要求：对拷的计算机配置需要一致，硬盘的容量需要一致<br /> 在一个机房中，服务器的种类不应超过三种，否则不便于维护<br /> 3. 网络批量安装，PXE无人值守安装<br /> 装好一台服务器搭建好PXE环境，将系统推送到所有终端设备，需要客户端连接，网卡尽量是千兆网卡，交换机尽量也要有足够的数据吞吐量，如果是百兆网卡在推送数量达到二十几台时会造成丢包的现象。<br /> <br /> 服务器的要求是：安全、稳定、可靠<br /> <br /> 服务器的常规优化：<br /> 1. 日志的管理<br /> 日志的轮替（滚动）、切割<br /> 2. 进程管理，主要是服务器健康管理<br /> 性能管理7090<br /> 内存占比不超过70%<br /> CPU占比不超过90%<br /> 当服务器超过这个限度时会加大服务器的死机风险<br /> 当有进程占用大量的资源时，应当查清楚源头<br /> 如果是正常的进程占用大量的资源，应当考虑集群的搭建<br /> 集群应当有监控服务器（监控服务器集群，通过协议来实现）<br /> 我们应当以正常的方式结束非法进程，当正常的方式失效时，我们考虑直接杀死进程<br /> 3. 服务器管理<br /> 关闭不需要的服务<br /> 原则：看不懂的不碰<br /> #windows下的服务设为手动启动时，开机不随系统启动启动，二是在被某个程序调用时才会开启<br /> 4. 本地安全策略：<br /> 密码策略：人离开时必须退出登录<br /> 复杂性：至少8位<br /> 大小写字母、数字、字符至少含有三种<br /> 不能和个人信息相关<br /> 不能使用现有英文单词<br /> window防火墙：<br /> ISA windows专业防火墙<br /> IP sec window的本地安全策略，个人版的最终配置就是使用IP sec<br /> 权限的划分：<br /> 服务器划分权限是为了防范内部人员<br /> 服务器上的东西越值钱，权限的划分越明显<br /> windows下的文件权限<br /> FAT16、FAT32文件系统上是，诶呦权限的，也就是说任何人都有所有权限<br /> NTFS文件系统有文件权限。<br /> 越新的文件系统越安全、支持越大的单个文件、性能越好、支持越大的分区，写入速度越快。<br /> <br /> 权限规则：<br /> 1. 本地访问，本地权限生效<br /> 网络访问，网络本地权限都生效（只有目录才能被共享）<br /> 2. 拒绝权限优先<br /> 如果有权限冲突，则拒绝权限优先<br /> 3. 权限的累加（windows特有）<br /> 一个人如果属于多个组，允许权限的累加<br /> 同样遵守拒绝优先<br /> 没有明确的允许时不能够访问的，和拒绝不一样<br /> 4. 权限的继承是为了让所有的新建文件都拥有默认权限（windows特有）<br /> <br /> 磁盘管理：<br /> 基本分区的大小是不能调整的（使用工具调整的不算调整）<br /> 基本分区：主分区、扩展分区、逻辑分区<br /> 使用工具调整是强制性调整，且不支持复杂的调整，如跨分区、跨硬盘操作<br /> windows中有高级的分区，支持分区的动态调整<br /> 动态磁盘支持分区大小调整<br /> 可以选择将磁盘转为动态磁盘，动态磁盘不存在主分区，所有分区级别一致<br /> 简单卷：只能在同一块磁盘上进行扩展（动态调整），当增加硬盘时自动升级为跨区卷<br /> 跨区卷：<br /> 需要至少两块或者两块以上的磁盘组成<br /> 没块磁盘的大小都可以不一样<br /> 支持动态调整分区大小<br /> 没有磁盘容错功能<br /> <br /> RAID整列<br /> RAID0：条带存储<br /> 需要两块或者两块以上的磁盘组成<br /> 每块硬盘的大小必须一致，读写效率高（多块硬盘进行同时读写）<br /> 损坏率最大<br /> RAID1：镜像存储<br /> 只能由两块或者两组硬盘组成<br /> 磁盘容量需要一致<br /> 磁盘利用率为50%<br /> 拥有磁盘容错功能<br /> RAID5：<br /> 由三块以上的硬盘组成<br /> 每块磁盘的大小必须一致<br /> 磁盘利用率为n-1块磁盘<br /> 拥有磁盘容错的功能<br /> RAID10：<br /> 先组建RAID1 ，再将RAID1组成RAID0<br /> RAID10使用较少，因为1U的服务器上只有三块硬盘仓位，2U的服务器支持，但是贵很多，如果买了2U的服务器，1U的服务器会闲置，替换代价大。<br /> 1U=4.4cm<br /> 软raid没有实际的使用价值，服务器上使用RAID卡。<br /> <br /> 综合布线<br /> 在墙上开槽不允许开横槽，横槽会影响整栋楼的刚性结构。<br /> <br /> 网线T568B的标准使用较多<br /> <br /> 将T568B的线序1/3和2/6线序对调就是T568A标准的线序。<br /> 在实际的传输中，也就只是1/3、2/6进行信息的传输。<br /> <br /> 线缆的连接：<br /> 直通线：两头都是同标准的接法，用作不同设备之间的连接<br /> 交叉线：一头使用T568A，一头使用T568B，用于同种设备之间的连接，计算机同路由器是同种设备。<br /> 全反线：一边为正常线序，另一头的线序全反过来<br /> 交换机之间虽然可以使用直通线连接，但是交换机线序的转换是需要消耗交换机资源的。<br /> <br /> 全反线：全反线是电脑用来连接交换机、路由器的管理端口的，而且只有一种用法，也叫做console线。<br /> <br /> 在布线的时候应当将所有的线做上标记，方便以后的维护。<br /> 交换机环路会造成数据风暴，会导致整个网络瘫痪。<br /> 交换机环路就是将一根线的两头插入到同一交换机的两个接口中。<br /> <br /> 以太网工作在数据链路层，所以我们平常使用的局域网就是以太网。<br /> <br /> 数据链路层：网卡—网线—交换机<br /> <br />

• 基础笔记综合整理
• 2018-09-27
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•   1697 次浏览

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