如何挂载另一个lvm硬盘

由于测试导致系统启动不了，需要将系统中的数据拷贝出来，所以想到将磁盘挂载到另一个能用的系统中进行拷贝，但是由于创建的系统都是用默认的方式创建的，所以一般的系统盘都是由两个分区组成，例如/dev/sda，/dev/sda1用来存放启动项，而/dev/sda2是一个逻辑卷，都是由/dev/VolGroup/lv_root、/dev/VolGroup/lv_home、/dev/VolGroup/lv_swap三部分组成的，由于逻辑卷的名字是一样的，所以这样导致将系统盘/dev/sdb挂载后，其中的逻辑卷部分不能挂载。

解决方法：

下面介绍分区格式为为Linux LVM的虚拟机挂载另一块的Linux LVM硬盘的方法：

在Hyper-V上添加要挂载的硬盘，开启虚拟机，启动好以后

#fdisk -l   //下面会看到所有硬盘的情况，sda是虚拟机自己的硬盘，sdb则是挂载上去的硬盘

[root@localhost ~]# fdisk -l

Disk /dev/sda: 1000.2 GB,  bytes
 heads,  sectors/track,  cylinders
Units = cylinders of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk identifier: 0x000c4715

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *                                Linux
Partition  does not end on cylinder boundary.
/dev/sda2                          8e  Linux LVM

Disk /dev/mapper/VolGroup-lv_root: 53.7 GB,  bytes
 heads,  sectors/track,  cylinders
Units = cylinders of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk identifier: 0x00000000

Disk /dev/mapper/VolGroup-lv_swap:  MB,  bytes
 heads,  sectors/track,  cylinders
Units = cylinders of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk identifier: 0x00000000

Disk /dev/mapper/VolGroup-lv_home: 937.6 GB,  bytes
 heads,  sectors/track,  cylinders
Units = cylinders of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk identifier: 0x00000000

Disk /dev/sdb: 120.0 GB,  bytes
 heads,  sectors/track,  cylinders
Units = cylinders of  *  =  bytes
Sector size (logical/physical):  bytes /  bytes
I/O size (minimum/optimal):  bytes /  bytes
Disk identifier: 0x000ec679

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *                                Linux
Partition  does not end on cylinder boundary.
/dev/sdb2                           8e  Linux LVM

#vgscan  //扫描所有卷组

[root@localhost ~]# vgscan
  Reading all physical volumes.  This may take a while...
  WARNING: Duplicate VG name VolGroup: Existing FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ (created here) takes precedence over JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX
  WARNING: Duplicate VG name VolGroup: Existing FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ (created here) takes precedence over JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX
  Found volume group "VolGroup" using metadata type lvm2
  Found volume group "VolGroup" using metadata type lvm2

#vgdisplay  //显示出多有卷组信息

[root@localhost ~]# vgdisplay
  WARNING: Duplicate VG name VolGroup: Existing FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ (created here) takes precedence over JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX
  WARNING: Duplicate VG name VolGroup: Existing FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ (created here) takes precedence over JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX
  WARNING: Duplicate VG name VolGroup: Existing JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX (created here) takes precedence over FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ
  --- Volume group ---
  VG Name               VolGroup
  System ID
  Format                lvm2
  Metadata Areas
  Metadata Sequence No
  VG Access             read/write
  VG Status             resizable
  MAX LV
  Cur LV
  Open LV
  Max PV
  Cur PV
  Act PV
  VG Size               111.30 GiB
  PE Size               4.00 MiB
  Total PE
  Alloc PE / Size        / 111.30 GiB
  Free  PE / Size        /
  VG UUID               JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX

  WARNING: Duplicate VG name VolGroup: Existing FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ (created here) takes precedence over JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX
  --- Volume group ---
  VG Name               VolGroup
  System ID
  Format                lvm2
  Metadata Areas
  Metadata Sequence No
  VG Access             read/write
  VG Status             resizable
  MAX LV
  Cur LV
  Open LV
  Max PV
  Cur PV
  Act PV
  VG Size               931.02 GiB
  PE Size               4.00 MiB
  Total PE
  Alloc PE / Size        / 931.02 GiB
  Free  PE / Size        /
  VG UUID               FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ

（主要是通过大小来区分的）

[root@localhost ~]# vgrename JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX vg01
  WARNING: Duplicate VG name VolGroup: Existing FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ (created here) takes precedence over JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX
  WARNING: Duplicate VG name VolGroup: Existing FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ (created here) takes precedence over JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX
  WARNING: Duplicate VG name VolGroup: Existing JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX (created here) takes precedence over FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ
  Volume group "VolGroup" successfully renamed to "vg01"

//重新命名挂载盘的卷组名，因为和虚拟机本身的卷组名是一样的所以LVM分区无法挂载，必须改名（要修改挂载盘的卷组名，这里要分编号哪个是挂载上去的），这里的类似于序列号的就是VG UUID，卷组名是一样的，只能靠VG UUID来修改卷组名

看到最下面Volume group "VolGroup00" successfully renamed to "vg01"则说明改名成功

#vgdisplay    //可以看到已经有一个改名为vg01

[root@localhost ~]# vgdisplay
  --- Volume group ---
  VG Name               vg01
  System ID
  Format                lvm2
  Metadata Areas
  Metadata Sequence No
  VG Access             read/write
  VG Status             resizable
  MAX LV
  Cur LV
  Open LV
  Max PV
  Cur PV
  Act PV
  VG Size               111.30 GiB
  PE Size               4.00 MiB
  Total PE
  Alloc PE / Size        / 111.30 GiB
  Free  PE / Size        /
  VG UUID               JTFVF9-ULu5-cHKu-T1p3-4HnB-Tk2p-BpjwHX

  --- Volume group ---
  VG Name               VolGroup
  System ID
  Format                lvm2
  Metadata Areas
  Metadata Sequence No
  VG Access             read/write
  VG Status             resizable
  MAX LV
  Cur LV
  Open LV
  Max PV
  Cur PV
  Act PV
  VG Size               931.02 GiB
  PE Size               4.00 MiB
  Total PE
  Alloc PE / Size        / 931.02 GiB
  Free  PE / Size        /
  VG UUID               FKsJuO--hHqs-MKVq-WLMl-2Sbh-0oh8NZ

#lvscan     //看到上面两个是挂在上去的磁盘，没有激活

[root@localhost ~]# lvscan
  inactive          '/dev/vg01/lv_root' [50.00 GiB] inherit
  inactive          '/dev/vg01/lv_home' [53.45 GiB] inherit
  inactive          '/dev/vg01/lv_swap' [7.85 GiB] inherit
  ACTIVE            '/dev/VolGroup/lv_root' [50.00 GiB] inherit
  ACTIVE            '/dev/VolGroup/lv_home' [873.25 GiB] inherit
  ACTIVE            '/dev/VolGroup/lv_swap' [7.77 GiB] inherit
可以看到下面ACTIVE是正在使用的系统盘，而上面是需要拷贝出来的系统盘

#vgchange -ay /dev/vg01     //激此卷组

[root@localhost ~]# vgchange -ay /dev/vg01
   logical volume(s) in volume group "vg01" now active

#lvscan    //看下vg01的卷组是否被激活

[root@localhost ~]# lvscan
  ACTIVE            '/dev/vg01/lv_root' [50.00 GiB] inherit
  ACTIVE            '/dev/vg01/lv_home' [53.45 GiB] inherit
  ACTIVE            '/dev/vg01/lv_swap' [7.85 GiB] inherit
  ACTIVE            '/dev/VolGroup/lv_root' [50.00 GiB] inherit
  ACTIVE            '/dev/VolGroup/lv_home' [873.25 GiB] inherit
  ACTIVE            '/dev/VolGroup/lv_swap' [7.77 GiB] inherit

#mkdir  /mnt/hdb    //新建一个文件夹用来作为挂载点

#mount  /dev/vg01/逻辑卷名（比如LogVol00）  /mnt/hdb    //挂载vg01/LogVol00

使用完以后要卸载

#umount  /mnt/hdb

#vgchange  -an  /dev/vg01   去除激活的LVM分区

修改过卷组名的这个硬盘是不能再启动了，应为默认启动引导是引导到VolGroup00卷组的，所以修改过卷组名的硬盘要想仍能重新启动的话，必须把卷组名修改会默认的VolGroup00

但是在已经有VolGroup00卷组的虚拟机上是不能修改的！这里我们单独建立一个分区格式不是Linux LVM格式的虚拟机来挂载硬盘，其格式为ext3的（显示为Linux）

#fdisk -l      //查看是否识别挂上的硬盘

#vgscan      //扫描卷组

#lvscan //查看要改名的卷组是否被激活，要是被激活的话则不能修改卷组名，如果直接修改的话会提示报错

#vgchange -an /dev/VolGroup00      //如果上一步骤是激活状态，则需用此命令修改为不激 活状态

#lvscan    //查看是否修改为不激活状态

#vgrename  vg01  VolGroup00    //修改为不激活状态则可以修改卷组名

在ext3格式分区的虚拟机上直接挂载Linux LVM分区的硬盘的方法如下：

#fdisk -l      //查看是否识别挂上的硬盘

#vgscan    //扫描卷组

#vgdisplay     //显示所有卷组

#lvscan    //查看挂载的磁盘的卷组是否处于激活的状态

#vgchange -ay /dev/VolGroup00    //如上步看到没有激活，则执行此命令

#mkdir  /mnt/hdb    //创建挂载点的文件夹

#mount  /dev/VolGroup00/LogVol00   /mnt/hdb    // 挂载，挂载后则可以访问/mnt/hdb

#umount  /mnt/hdb    //卸载磁盘

#vgchange -an /dev/VolGroup00    //去除挂载磁盘卷组的激活状态

补充如果要设置开机自动加载LVM分区：

vim /etc/fstab

加入

/dev/vg110/LogVol01     /wwwroot/               ext4    defaults        0 0