Loading... <h1 style="border-bottom-color:#cccccc;border-bottom-width:2px;border-bottom-style:solid;padding:0px 4px 0px 0px;text-align:center;margin:0px 0px 20px"><span style="color:#c0504d">RAID浅析</span></h1> <h1 style="text-align: left">目录索引</h1> <h2>一、定义</h2> <p></p> <h2>二、特点</h2> <p></p> <h2>三、常用RAID级别</h2> <p> </p> <h2>四、RAID实现方式</h2> <p></p> <p><span style="line-height: 25.6px"></span></p> <h2>五、实际环境测试</h2> <p></p> <h3><span style="font-family:幼圆">一、定义:</span></h3> <p style="text-indent: 2em;line-height: 1.5em">磁盘阵列(Redundant Arrays of Independent Disks,RAID),有“独立磁盘构成的具有冗余能力的阵列”之意。</p> <p style="text-indent: 2em;line-height: 1.5em">独立磁盘冗余阵列(RAID,redundant array of independent disks)是把相同的数据存储在多个硬盘的不同的地方(因此,冗余地)的方法。通过把数据放在多个硬盘上,输入输出操作能以平衡的方式交叠,改良性能。因为多个硬盘增加了平均故障间隔时间(MTBF),储存冗余数据也增加了容错。</p> <h3><span style="font-family:幼圆">二、特点:</span></h3> <p><span style="line-height: 1.6"> 可以提高IO能力:</span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 磁盘并行读写</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> 可以</span><span style="line-height: 1.6">提高耐用性:</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 磁盘冗余来实现</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">RAID实现的方式:</span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 硬RAID</span></p> <p><span style="line-height: 1.6"> 外接式磁盘阵列:通过扩展卡提供适配能力</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 内接式RAID:主板集成RAID控制器</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> Software RAID:</span></p> <h3><span style="font-family:幼圆">三、常用RAID级别:</span></h3> <p><span style="line-height: 1.6"> 级别:level:<span style="line-height: 24px;font-family: arial, helvetica, sans-serif;font-size: 16px">多块磁盘组织在一起的工作方式有所不同</span></span></p> <p> <span style="line-height: 1.6"> RAID-0:条带卷,strip;<span>把连续的数据分散到多个磁盘上存取;</span></span></p> <p><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 优点:读、写性能提升</span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 可用空间:N*min(s1,s2,…)</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 缺点:无容错能力</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 最少磁盘数:2,2+</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> <img src="//cto.wang/usr/uploads/2016/07/20160703161758-66.png" title="1460367495401362.png" alt="RAID 0.png" /></span></p> <p><span style="line-height: 1.6"> <br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> <span style="line-height: 1.6"> </span>RAID-1:镜像卷,mirror;</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 特点:</span>读性能提升,<span style="line-height: 25.6px">有冗余能力</span></span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> 缺点:磁盘空间利用率低,<span style="line-height: 25.6px">写性能略有下降</span></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 可用空间:1*min</span><span style="line-height: 1.6">(s1,s2,…)</span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 最少次盘数:2,2+</span></p> <p><span style="line-height: 1.6"> <img src="//cto.wang/usr/uploads/2016/07/20160703161758-89.png" title="1460367708547558.png" alt="RAID 1.png" /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> RAID-5:</span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 优点:读、写性能提升</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 可用空间:(N-1)*min</span><span style="line-height: 1.6">(s1,s2,…)</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">有容错能力:1块磁盘</span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 最少磁盘数:3,3+</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> <img src="//cto.wang/usr/uploads/2016/07/20160703161758-2.png" title="1460367966687174.png" alt="RAID 5.png" /></span></p> <p> <span style="line-height: 1.6"> RAID-6</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> 优点L:读、写性能提升</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 可用空间:(N-2)*min</span><span style="line-height: 1.6">(s1,s2,…)</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">有容错能力:2块磁盘</span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 最少磁盘数:4,4+</span></p> <p><span style="line-height: 1.6"> <img src="//cto.wang/usr/uploads/2016/07/20160703161758-15.png" title="1460384115712174.png" alt="RAID 6.png" /></span></p> <p> <span style="line-height: 1.6"> RAID10:</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 优点:读、写性能提升</span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 可用空间:N*min</span><span style="line-height: 1.6">(s1,s2,…)/2</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">有容错能力:每组镜像最多只能坏一块</span></p> <p><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 最少磁盘数:4,4+</span><span style="line-height: 1.6"> </span></p> <p><span style="line-height: 1.6"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-20.png" title="1460367982365747.png" alt="RAID 10.png" /> </span></p> <p><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">JBOD:Just a Bunch Disks</span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 功能:将多块磁盘的空间合并一个大的连续空间使用</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 可用空间:sum(s1,s2,….)</span></p> <h3><span style="line-height: 25.6px">四、RAID实现方式:</span></h3> <p><span style="line-height: 25.6px"> 相关命令:</span></p> <p><span style="line-height: 1.6"> CentOS 6上的RAID的实现</span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">结合内核中的md(multi devices)</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">mdadm工具:模式化的工具</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">命令的语法格式:madadm [mode] <raiddevice> [optiongs] <component-devices></span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">支持的RAID级别:LINEAE,RAID0,RAID1,RAID4,RAID5,RAID6,RAID10</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">模式:</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 创建:-C</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">装配:-A</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">监控:-F</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> 管理:-f, -r,-c</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"><raiddevice>:/dev/md#</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"><component-devices>:任意块设备</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6"> </span><span style="line-height: 1.6">-C:创建模式</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> -n #:使用#个快设备来创建此RAID</span></p> <p><span style="line-height: 1.6"> -l #:指明要创建的RAID的级别</span></p> <p><span style="line-height: 1.6"> -a {yes|no}:自动创建目标RAID设备的设备文件</span></p> <p><span style="line-height: 1.6"> -c CHUNK_SIZE:指明块大小</span></p> <p><span style="line-height: 1.6"> -x #:指明空闲盘的个数</span></p> <p><span style="line-height: 1.6"> -D:显示raid的详细信息:mdadm -D /dev/md#</span></p> <p><span style="line-height: 1.6"> 管理模式:</span></p> <p> <span style="line-height: 1.6"> -f:标记制定磁盘为损坏</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> -a:添加磁盘</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> -r:移除磁盘</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> 观察md的状态:</span></p> <p> <span style="line-height: 1.6"> cat /proc/mdstat</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> 停止md设备:</span></p> <p> <span style="line-height: 1.6"> mdadm -S /dev/md#</span><span style="line-height: 1.6"><br /></span></p> <p><span style="line-height: 1.6"> watch命令</span></p> <p> <span style="line-height: 1.6"> -n #:刷新间隔,单位是秒</span><span style="line-height: 1.6"><br /></span></p> <p> <span style="line-height: 1.6"> watch -n# ‘COMMAND’</span></p> <h3><span style="line-height: 1.6">五、实际环境测试:</span></h3> <p><span style="line-height: 1.6"> 实验利用4块盘配置RAID5,为此给虚拟机添加4块5G硬盘,测试环境如图所示:<br /></span></p> <p><span style="line-height: 1.6"> <br /></span></p> <p><span style="line-height: 1.6"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-20-1.png" title="1460386628981272.png" alt="实操环境.png" /></span></p> <p><span style="line-height: 1.6"> 实验步骤:<br /></span></p> <p><span style="line-height: 1.6"> 1、用#fdisk -l命令来确认可识别新添加硬盘,由下图可知:新增设备为/dev/sd[b,c,d,e]四块硬盘。<br /></span></p> <p><span style="line-height: 1.6"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-31.png" title="1460386990732180.png" alt="确认新加磁盘.png" /></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"> </span><span style="line-height: 25.6px"> </span><span style="line-height: 25.6px"> </span><span style="line-height: 25.6px"> </span><span style="line-height: 25.6px"> </span>2、用#rpm -qa|grep mdadm命令查看是否已安装mdadm软件,若无输出则证明该系统未安装相关软件,则使用#yum install madam进行安装。</span></p> <p><span style="line-height: 1.6"> 如图所示,本系统已经安装相关软件。<br /></span></p> <p><span style="line-height: 1.6"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-13.png" title="1460387386828399.png" alt="确认安装mdadm软件.png" /></span></p> <p><span style="line-height: 1.6"> 3、创建RAID5至少需要3块硬盘,所以本次实验中将/dev/sd[b,c,d]三块硬盘作为活动盘,剩下的一块硬盘/dev/sde作为热备盘。由于硬盘为<br /></span></p> <p><span style="line-height: 1.6"> 新添加硬盘,所以对四块硬盘进行分区并修改分区类型,命令为:fdisk /dev/sdb;<span style="line-height: 25.6px">fdisk /dev/sdc;<span style="line-height: 25.6px">fdisk /dev/sdd;<span style="line-height: 25.6px">fdisk /dev/sde,</span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> 分区时将分区类型id改成fd,操作完成后用命令#fdisk -l /dev/sd[b,c,d,e] 如图所示:<br /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-93.png" title="1460388883572861.png" alt="新磁盘分区完成.png" /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> 4、分区完成,开始创建RAID,命令:#mdadm -C /dev/md5 -n3 -l5 -ayes -x1 /dev/sd[b,c,d,e]1<br /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-50.png" title="1460389022754438.png" alt="创建RAID5.png" /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> 5、用#cat /proc/mdstat 查看刚刚创建的RAID5状态,以及用#mdadm -D /dev/md5查看所建RAID5的详细信息<br /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-85.png" title="1460389277389670.png" alt="查看RAID5创建状态.png" /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-90.png" title="1460389399448209.png" alt="新建RAID5详细信息.png" /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> 6、将新建好的RAID5添加到RAID配置文件/etc/mdadm.conf文件中,命令为:<br /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> #echo DEVICE /dev/sd[b,c,d,e]1 >> /etc/mdadm.conf<br /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> #mdadm -Ds >> /etc/mdadm.conf<br /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> 然后,用cat命令查看配置文件信息<br /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-75.png" title="1460390654126454.png" alt="RAID配置文件信息.png" /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> 7、对新建好的磁盘阵列进行格式化,命令为#mkfs.ext4 /dev/md5或#mkfs -t ext4 /dev/md5<br /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-65.png" title="1460390784160517.png" alt="磁盘阵列格式化.png" /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> 8、在/下建立名为/testraid5的挂载点,并将其挂载,命令:#mkdir /testraid5;#mount /dev/md5 /testraid5<br /></span></span></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-40.png" title="1460391147328221.png" alt="挂载.png" /></span></span></span></span></p> <p><span style="line-height: 25.6px"> 9、挂载完成后,<span>为了下次开机还能正常使用我们的RAID设备,需要将挂载的信息写入/etc/fstab 文件中</span></span></p> <p><span style="line-height: 25.6px"><span> <img src="//cto.wang/usr/uploads/2016/07/20160703161759-16.png" title="1460391435402031.png" alt="编辑配置文件.png" /></span></span></p> <p><span style="line-height: 25.6px"><span> 10、至此,本次创建RAID5实验结束。<br /></span></span></p> <p><span style="line-height: 1.6"><span style="line-height: 25.6px"><span style="line-height: 25.6px"><span style="line-height: 25.6px"> <br /></span></span></span></span></p> <p><span style="line-height: 25.6px"><br /></span></p> <p class="ue_t"></p> <p></p> 最后修改:2021 年 12 月 10 日 10 : 53 AM © 允许规范转载 赞赏 如果觉得我的文章对你有用,请随意赞赏 赞赏作者 支付宝微信