<p class="shortdesc"></p> <p class="p">从上节的LVM架构图中可以看出，使用LVM管理云硬盘的基本操作步骤如下：</p> <ol class="ol" id="BuildLVM__ol_yqt_vss_slb"> <li class="li"><a class="xref" href="#BuildLVM__p_xhm_xvj_tlb">安装LVM</a>。</li> <li class="li"><a class="xref" href="#BuildLVM__p_sx1_jsj_tlb">将云硬盘创建为物理卷</a>。</li> <li class="li"><a class="xref" href="#BuildLVM__p_tnv_xvj_tlb">将多个物理卷组合成卷组</a>。</li> <li class="li"><a class="xref" href="#BuildLVM__p_cgc_yvj_tlb">在卷组中创建逻辑卷</a>。</li> <li class="li"><a class="xref" href="#BuildLVM__p_hhh_yvj_tlb">在逻辑卷之上创建文件系统</a>。</li> </ol> <section class="section" id="BuildLVM__section_lcb_mx3_tlb"><h2 class="doc-tairway">背景信息</h2> <p class="p">本文以/dev/vdb、/dev/vdc和/dev/vdd三块云硬盘为例说明如何创建LVM。如下图所示，系统已经挂载了三块云硬盘，大小是20GB。</p> <img class="image" id="BuildLVM__image_t3n_xrj_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183925-138d754d91f8.png"> </section> <section class="section" id="BuildLVM__section_gkz_mx3_tlb"><h2 class="doc-tairway">前提条件</h2> <p class="p">已经完成云硬盘的创建，并且挂载在对应的云服务器上。请参见<span class="xref">创建云硬盘</span>。</p> </section> <section class="section" id="BuildLVM__section_kdt_nx3_tlb"><h2 class="doc-tairway">注意事项</h2> <p class="p">在单台实例已挂载多块云硬盘创建LVM时，由于快照只能针对独立的每个云硬盘创建，当使用LVM后，使用快照回滚云盘时会造成数据差异。</p> </section> <section class="section" id="BuildLVM__section_cj2_4x3_tlb"><h2 class="doc-tairway">操作步骤</h2> <p class="p" id="BuildLVM__p_xhm_xvj_tlb"><strong class="ph b">步骤一：安装LVM</strong></p> <ol class="ol" id="BuildLVM__ol_jgv_csj_tlb"> <li class="li">执行如下命令，检查系统是否安装过LVM。<pre class="pre codeblock"><code>rpm -qa |grep lvm2</code></pre><ul class="ul" id="BuildLVM__ul_j5w_2sj_tlb"> <li class="li">如果出现如下显示信息，则说明已经安装，可以跳过步骤一，直接执行<a class="xref" href="#BuildLVM__p_sx1_jsj_tlb">步骤二</a>。<img class="image" id="BuildLVM__image_gyq_kwj_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183925-1e71d35e9892.png"></li> <li class="li">如果没有出现如上显示信息，则执行<a class="xref" href="#BuildLVM__p_sx1_jsj_tlb">步骤二</a>。</li> </ul></li> <li class="li">执行如下命令，安装LVM。<pre class="pre codeblock"><code>yum install lvm2</code></pre><p class="p">执行后，若出现如下信息，则说明安装成功。</p><img class="image" id="BuildLVM__image_izf_mwj_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183925-1fac79649845.png"></li> </ol> <p class="p" id="BuildLVM__p_sx1_jsj_tlb"><strong class="ph b">步骤二：将云硬盘创建为物理卷</strong></p> <ol class="ol" id="BuildLVM__ol_m4t_wtj_tlb"> <li class="li">以root用户登录云服务器。</li> <li class="li">执行如下命令，查看当前设备挂载的云硬盘。<pre class="pre codeblock"><code>fdisk -l</code></pre><img class="image" id="BuildLVM__image_jfg_nwj_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183926-159b0e959769.png"><p class="p">从上述的显示信息中我们可以看出，当前系统挂载了三块云硬盘，分别是/dev/vdb、/dev/vdc和/dev/vdd。</p></li> <li class="li">创建物理卷，将希望添加到卷组的所有分区或者云硬盘创建为物理卷。将整个硬盘创建为物理卷的命令为：<pre class="pre codeblock"><code>pvcreate <磁盘设备名1> <磁盘设备名2 > … <磁盘设备名n></code></pre><p class="p">多个磁盘之间用空格来分隔。</p><p class="p">本示例中，执行<code class="ph codeph">pvcreate /dev/vdb /dev/vdc /dev/vdd</code>命令，显示如下。</p><img class="image" id="BuildLVM__image_f2h_4wj_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183926-191d24fb9dd7.png"></li> <li class="li">执行如下命令，查看新创建的物理卷详细信息。<pre class="pre codeblock"><code>pvdisplay</code></pre><img class="image" id="BuildLVM__image_ctx_4wj_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183926-1a6147cb9e11.png"><p class="p">从显示信息中，我们可以看到新创建的三个物理卷，分别是/dev/vdb、/dev/vdc 、/dev/vdd。</p></li> </ol> <p class="p" id="BuildLVM__p_tnv_xvj_tlb"><strong class="ph b">步骤三：创建卷组</strong></p> <ol class="ol" id="BuildLVM__ol_ghn_25j_tlb"> <li class="li">将多个物理卷创建为一个卷组。<pre class="pre codeblock"><code>vgcreate <卷组名> <物理卷名称1> <物理卷名称2> … <物理卷名称n></code></pre><p class="p">本示例中，执行 <code class="ph codeph">vgcreate lvm_example /dev/vdb /dev/vdc /dev/vdd</code>。</p><img class="image" id="BuildLVM__image_iyz_pwj_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183926-193994019f55.png"><p class="p">如果出现如上提示信息，则说明卷组创建成功。</p></li> <li class="li"> 查看卷组详细信息<pre class="pre codeblock"><code>vgdisplay</code></pre><img class="image" id="BuildLVM__image_ccx_qwj_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183926-1996ad879685.png"></li> <li class="li">（可选）卷组创建完成后，如果想将新的物理卷添加到该卷组，可以执行如下命令。<pre class="pre codeblock"><code>vgextend <卷组名> <物理卷名称1></code></pre></li> </ol> <p class="p" id="BuildLVM__p_cgc_yvj_tlb"><strong class="ph b">步骤四：在卷组中创建逻辑卷</strong></p> <ol class="ol" id="BuildLVM__ol_gqc_gvj_tlb"> <li class="li">创建逻辑卷。<pre class="pre codeblock"><code>lvcreate -L <逻辑卷大小> -n <逻辑卷名称> <卷组名称></code></pre><p class="p">本示例中，执行<code class="ph codeph">lvcreate -L 20G -n lv1 lvm_example</code>。</p><img class="image" id="BuildLVM__image_tzc_ywj_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183926-1b0794599d00.png"></li> <li class="li">查看逻辑卷详情。<pre class="pre codeblock"><code>lvdisplay</code></pre><img class="image" id="BuildLVM__image_pdw_ywj_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183926-117342cd9178.png"></li> </ol> <p class="p" id="BuildLVM__p_hhh_yvj_tlb"><strong class="ph b">步骤五：创建并挂载文件系统</strong></p> <ol class="ol" id="BuildLVM__ol_k1q_kvj_tlb"> <li class="li">创建文件系统。<pre class="pre codeblock"><code>mkfs.<文件格式> <逻辑卷路径></code></pre><p class="p">本示例中，执行<code class="ph codeph">mkfs.ext3 /dev/lvm_example/lv1</code>。</p></li> <li class="li"> 创建挂载目录。<pre class="pre codeblock"><code>mkdir <挂载目录></code></pre><p class="p">示例</p><pre class="pre codeblock"><code>mkdir /Data</code></pre></li> <li class="li"> 挂载逻辑卷。<pre class="pre codeblock"><code>mount <逻辑卷路径> <挂载目录></code></pre><p class="p">示例</p><pre class="pre codeblock"><code>mount /dev/lvm_example/lv1 /Data</code></pre></li> <li class="li">查看挂载是否成功。<pre class="pre codeblock"><code>df -h</code></pre><img class="image" id="BuildLVM__image_dyz_qn4_tlb" src="https://obs-cn-shanghai.fincloud.pinganyun.com/pacloud/20220711183926-1243a52c938d.png" width="800"><p class="p"> 可以看到该逻辑卷已经成功挂载在/Data下。</p></li> </ol> </section>