LVM是逻辑盘卷管理（Logical Volume Manager）的简称，它是Linux环境下对磁盘分区进行管理的一种机制，LVM是建立在硬盘和分区之上的一种逻辑层，来提高磁盘分区管理的灵活性。
LVM工作原理：是通过将底层的物理硬盘抽象的封装起来，然后以逻辑卷的方式呈现给上层应用。在传统的磁盘管理机制中，我们的上层应用是直接访问文件系统，从而对底层的物理硬盘进行读取，而在LVM中，其通过对底层的硬盘进行封装，当我们对底层的物理硬盘进行操作时，其不再是针对于分区进行操作，而是通过一个叫做逻辑卷的东西来对其进行底层的磁盘管理操作。比如说增加一个物理硬盘，这个时候上层的服务是感觉不到的，因为呈现给上层服务的是以逻辑卷的方式。
LVM最大的特点就是可以对磁盘进行动态管理。因为逻辑卷的大小是可以动态调整的，而且不会丢失现有的数据。如果我们新增加了硬盘，其也不会改变现有上层的逻辑卷。作为一个动态磁盘管理机制，逻辑卷技术大大提高了磁盘管理的灵活性。
前面谈到，LVM是在磁盘分区和文件系统之间添加的一个逻辑层，来为文件系统屏蔽下层磁盘分区布局，提供一个抽象的存储卷，在存储卷上建立文件系统。首先我们讨论以下几个LVM术语：
物理存储介质（PhysicalStorageMedia）指系统的物理存储设备：磁盘，如：/dev/hda、/dev/sda等，是存储系统最底层的存储单元。
物理卷（Physical Volume，PV）指磁盘分区或从逻辑上与磁盘分区具有同样功能的设备（如RAID），是LVM的基本存储逻辑块，但和基本的物理存储介质（如分区，磁盘等）比较，却包含有与LVM相关的管理参数。
卷组（Volume Group，VG）类似于非LVM系统中物理磁盘，其由一个或多个物理卷PV组成。可以在卷组上创建一个或多个LV（逻辑卷）
逻辑卷（Logical Volume，LV）类似于非LVM系统中的磁盘分区，逻辑卷建立在卷组VG之上。在逻辑卷LV之上可以建立文件系统（比如/home或/usr等）
物理块（Physical Extent，PE）每一个物理卷PV被划分为称为PE的基本单元，具有唯一编号的PE是可以被LVM寻址的最小单元。PE的大小是可配置的，默认为4MB。所以物理卷由大小等同的基本单元PE组成。
逻辑块（Logical Extent，LE）逻辑卷LV也被划分为可被寻址的基本单位，称为LE。在同一个卷组中，LE的大小和PE是相同的，并且一一对应。
简单来说：
PV：物理磁盘的分区
VG：LVM中的物理的磁盘分区，必须加入VG，可以将VG理解为一个仓库或者几个大的硬盘。
LV：从VG中划分的逻辑分区
如下图示PV、VG、LV三者关系：
LVM：Logical Volume Manager，Version：2
? dm: device mapper：将一个或多个底层块设备组织成一个逻辑设备的模块
? 设备名：/dev/dm-#
? 软链接：
/dev/mapper/VG_NAME-LV_NAME
/dev/mapper/vol0-root
/dev/VG_NAME/LV_NAME
/dev/vol0/root
LVM可以弹性的更改LVM的容量
通过交换PE进行资料的转换，将原来LV内的PE转移到其他的设备中以降低LV的容量，或将其他设备中的PE加到LV中以加大容量。
1）显示pv信息
pvs：简要pv信息显示
pvdisplay
2）创建pv
pvcreate /dev/Device
例子：
使用磁盘分区创建物理卷（pv）
[root@centos6 ~]#fdisk /dev/sdb -l #查看磁盘分区ID类型
Disk /dev/sdb: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x4074ebc8
Device Boot Start End Blocks Id System
/dev/sdb1 1 132 1060258+ 8e Linux LVM
/dev/sdb2 133 394 2104515 8e Linux LVM
#8e为磁盘分区类型为LVM管理器
创建pv：
[root@centos6 ~]#pvcreate /dev/sdb{1,2} #创建pv卷
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdb2" successfully created
提示：物理卷创建成功
[root@centos6 ~]#pvs #查看pv卷
PV VG Fmt Attr PSize PFree
/dev/sdb1 lvm2 ---- 1.01g 1.01g
/dev/sdb2 lvm2 ---- 2.01g 2.01g
[root@centos6 ~]#pvdisplay #查看pv卷详细信息
"/dev/sdb1" is a new physical volume of "1.01 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb1 #设备名
VG Name #VG名（新创建pv未加入到VG组显示空名VG组）
PV Size 1.01 GiB #PV容量
Allocatable NO
PE Size 0 #PE大小（需指定PE大小）
Total PE 0 #PE数量
Free PE 0 #PE使用空间
Allocated PE 0
PV UUID EPcGil-E7Ng-08fP-FS1u-tzqR-MMtc-1kxX0k
"/dev/sdb2" is a new physical volume of "2.01 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb2
VG Name
PV Size 2.01 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID pqURc6-F7d9-nKmp-3KGi-rzdE-S9yD-Azm6s4
?1）显示卷组
vgs
vgdisplay
?2）创建卷组
vgcreate [-s #[kKmMgGtTpPeE]] VolumeGroupName PhysicalDevicePath [PhysicalDevicePath...]
?3）管理卷组
vgextend VolumeGroupName PhysicalDevicePath [PhysicalDevicePath...] #扩展卷组
vgreduce VolumeGroupName PhysicalDevicePath [PhysicalDevicePath...] #移除卷组
?4）删除卷组
先做pvmove，再做vgremove
例子：
[root@centos6 ~]#vgcreate -s 16M vg0 /dev/sdb{1,2} #创建vg卷组，-s 指定PE大小
Volume group "vg0" successfully created #提示创建卷组成功
[root@centos6 ~]#pvs #
PV VG Fmt Attr PSize PFree
/dev/sdb1 vg0 lvm2 a--u 1.00g 1.00g
/dev/sdb2 vg0 lvm2 a--u 2.00g 2.00g
[root@centos6 ~]#pvdisplay #查看pv详细信息
--- Physical volume ---
PV Name /dev/sdb1
VG Name vg0 #将pv加入vg组
PV Size 1.01 GiB / not usable 11.41 MiB #PV大小（其中not usable表示不够PE分配，PE是以16M来分配PV大小）
Allocatable yes
PE Size 16.00 MiB #PE大小（手动指定）
Total PE 64 #PE数量（PE数量*PE大小得出设备大小）
Free PE 64 #可用PE数量
Allocated PE 0 #PE未被分配给逻辑卷
PV UUID EPcGil-E7Ng-08fP-FS1u-tzqR-MMtc-1kxX0k
--- Physical volume ---
PV Name /dev/sdb2
VG Name vg0
PV Size 2.01 GiB / not usable 7.19 MiB
Allocatable yes
PE Size 16.00 MiB
Total PE 128
Free PE 128
Allocated PE 0
PV UUID pqURc6-F7d9-nKmp-3KGi-rzdE-S9yD-Azm6s4
[root@centos6 ~]#vgs #查看卷组
VG #PV #LV #SN Attr VSize VFree
vg0 2 0 0 wz--n- 3.00g 3.00g #vg大小3G
[root@centos6 ~]#vgdisplay #查看卷组详细信息
--- Volume group ---
VG Name vg0
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 3.00 GiB #VG大小
PE Size 16.00 MiB #PE大小
Total PE 192 #PE数量
Alloc PE / Size 0 / 0
Free PE / Size 192 / 3.00 GiB
VG UUID dpILvC-q23x-WCCH-Z1Or-SEH6-xdwS-Qope7b
[root@centos6 ~]#blkid
/dev/sda1: UUID="fcf2e544-0db0-4f27-9bdd-380bddaaee4d" TYPE="ext4"
/dev/sda2: UUID="d7c928d9-40b6-420e-99de-74877dbdccf5" TYPE="ext4"
/dev/sda3: UUID="d9193730-2fc6-44d0-93cb-a8b7a120a5bf" TYPE="ext4"
/dev/sda5: UUID="858ff62c-536c-4e5a-b7aa-bc949fcf20d2" TYPE="swap"
/dev/sdb1: UUID="EPcGil-E7Ng-08fP-FS1u-tzqR-MMtc-1kxX0k" TYPE="LVM2_member" #卷组成员
/dev/sdb2: UUID="pqURc6-F7d9-nKmp-3KGi-rzdE-S9yD-Azm6s4" TYPE="LVM2_member" #卷组成员
?1）显示逻辑卷
lvs
Lvdisplay
?2）创建逻辑卷
lvcreate -L #[mMgGtT] -n NAME VolumeGroup
lvcreate -l 60%VG -n mylv testvg
lvcreate -l 100%FREE -n yourlv testvg
选项：
-L ：以VG大小分配 例子：-L +5G
-l ：以PE大小分配 例子：-l +100
-l 100%FREE：100%FREE将vg剩余空间创建逻辑卷
+5G：表示在原来空间增加5G空间
例：原1G空间增加5G空间，则空间为6G空间
5G：表示在原有空间增加到5G空间，并不是在原有空间加5G空间。
例：原1G空间增加到5G，则空间为5G空间
?3）删除逻辑卷
lvremove /dev/VG_NAME/LV_NAME
?4）重设文件系统大小
fsadm [options] resize device [new_size[BKMGTEP]]
resize2fs [-f] [-F] [-M] [-P] [-p] device [new_size]
例子：1、创建逻辑卷
[root@centos6 ~]#lvcreate -n lv0 -l 100 vg0 #创建逻辑卷
Logical volume "lv0" created.
[root@centos6 ~]#lvs #查看逻辑卷
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv0 vg0 -wi-a----- 1.56g #lv0大小1.56G
[root@centos6 ~]#lvdisplay #查看逻辑卷详细信息
--- Logical volume ---
LV Path /dev/vg0/lv0 #lv路径不是真正的，而是软链接名真正是dm-0
LV Name lv0
VG Name vg0
LV UUID YTBvNy-3sg3-BBao-HOsf-d1uQ-oJVX-h6VKNb
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:04:15 +0800
LV Status available
# open 0
LV Size 1.56 GiB
Current LE 100
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
[root@centos6 ~]#ll /dev/vg0/lv0 #查看lv路径
lrwxrwxrwx. 1 root root 7 Jun 8 19:04 /dev/vg0/lv0 -> ../dm-0
创建另一个逻辑卷，先查看卷组空间情况
[root@centos6 ~]#vgs #查看卷组剩余空间
VG #PV #LV #SN Attr VSize VFree
vg0 2 1 0 wz--n- 3.00g 1.44g #VFree表示剩余空间大小
[root@centos6 ~]#vgdisplay #查看vg详细信息
--- Volume group ---
VG Name vg0
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 2
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 3.00 GiB
PE Size 16.00 MiB
Total PE 192
Alloc PE / Size 100 / 1.56 GiB
Free PE / Size 92 / 1.44 GiB #PE剩余大小，92个PE，容量为1.44G
VG UUID dpILvC-q23x-WCCH-Z1Or-SEH6-xdwS-Qope7b
[root@centos6 ~]#lvcreate -n lv1 -l 100%FREE vg0 #创建逻辑卷，将vg剩余空间创建逻辑卷
Logical volume "lv1" created.
[root@centos6 ~]#lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv0 vg0 -wi-a----- 1.56g
lv1 vg0 -wi-a----- 1.44g
[root@centos6 ~]#vgdisplay
--- Volume group ---
VG Name vg0
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 0
Max PV 0
Cur PV 2
Act PV 2
VG Size 3.00 GiB
PE Size 16.00 MiB
Total PE 192
Alloc PE / Size 192 / 3.00 GiB
Free PE / Size 0 / 0 #PE空间为0，表示不能再创建逻辑卷
VG UUID dpILvC-q23x-WCCH-Z1Or-SEH6-xdwS-Qope7b
[root@centos6 ~]#ll /dev/mapper/vg0-lv1 #查看lv1真正名
lrwxrwxrwx. 1 root root 7 Jun 8 19:18 /dev/mapper/vg0-lv1 -> ../dm-1
2、对新创建逻辑卷创建文件系统
[root@centos6 ~]#blkid /dev/vg0/lv0 #查看逻辑卷是否有文件系统
[root@centos6 ~]#mkfs.ext4 /dev/vg0/lv0 #逻辑卷增加文件系统
[root@centos6 ~]#mkfs.ext4 /dev/vg0/lv1 #逻辑卷增加文件系统
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
94272 inodes, 376832 blocks
18841 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=385875968
12 block groups
32768 blocks per group, 32768 fragments per group
7856 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 28 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@centos6 ~]#blkid #查看逻辑卷文件系统
/dev/sda1: UUID="fcf2e544-0db0-4f27-9bdd-380bddaaee4d" TYPE="ext4"
/dev/sda2: UUID="d7c928d9-40b6-420e-99de-74877dbdccf5" TYPE="ext4"
/dev/sda3: UUID="d9193730-2fc6-44d0-93cb-a8b7a120a5bf" TYPE="ext4"
/dev/sda5: UUID="858ff62c-536c-4e5a-b7aa-bc949fcf20d2" TYPE="swap"
/dev/sdb1: UUID="EPcGil-E7Ng-08fP-FS1u-tzqR-MMtc-1kxX0k" TYPE="LVM2_member"
/dev/sdb2: UUID="pqURc6-F7d9-nKmp-3KGi-rzdE-S9yD-Azm6s4" TYPE="LVM2_member"
/dev/mapper/vg0-lv0: UUID="f5874770-f912-49b0-abd5-0d7f08e727b1" TYPE="ext4"
/dev/mapper/vg0-lv1: UUID="ae47578c-1ad1-48f4-aff5-b277ed1b62ba" TYPE="ext4"
#新增逻辑卷成员添加文件系统
3、增加开机启动自动挂载逻辑卷
[root@centos6 ~]#vim /etc/fstab #增加开机自动挂载逻辑卷
。。。。
UUID=f5874770-f912-49b0-abd5-0d7f08e727b1 /mnt/lv0 ext4 defaults 0 0 #增加逻辑卷挂载信息
提示：此例只挂载一个逻辑卷，另外一个可以自行尝试挂载。
[root@centos6 ~]#mkdir /mnt/lv0 #创建挂载点
[root@centos6 ~]#mount -a #自动挂载
[root@centos6 ~]#df -h #查看挂载情况
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 20G 4.4G 15G 24% /
tmpfs 491M 72K 491M 1% /dev/shm
/dev/sda3 9.8G 23M 9.2G 1% /app
/dev/sda1 283M 35M 233M 14% /boot
/dev/mapper/vg0-lv0 1.6G 2.4M 1.5G 1% /mnt/lv0
?1）扩展逻辑卷：
lvextend -L [+]#[mMgGtT] /dev/VG_NAME/LV_NAME
resize2fs /dev/VG_NAME/LV_NAME
lvresize -r -l +100%FREE /dev/ VG_NAME/LV_NAME
-r ：扩展同时同步文件系统
?2）缩减逻辑卷：
umount /dev/VG_NAME/LV_NAME
e2fsck -f /dev/VG_NAME/LV_NAME
resize2fs /dev/VG_NAME/LV_NAME #[mMgGtT]
lvreduce -L [-]#[mMgGtT] /dev/VG_NAME/LV_NAME
mount
1、例子：扩展空间案例
模拟逻辑卷空间不够用，需要扩展，但是卷组也没有空间，需要增加物理磁盘扩展卷组给逻辑卷
1）模拟逻辑卷空间不足
[root@centos6 ~]#dd if=/dev/zero of=/mnt/lv0/f1 bs=1M count=500 #创建500文件
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 10.5683 s, 49.6 MB/s
[root@centos6 ~]#dd if=/dev/zero of=/mnt/lv0/f2 bs=1M count=500 conv=fdatasync
500+0 records in
500+0 records out
524288000 bytes (524 MB) copied, 0.736254 s, 712 MB/s
[root@centos6 ~]#df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 20G 4.4G 15G 24% /
tmpfs 491M 72K 491M 1% /dev/shm
/dev/sda3 9.8G 23M 9.2G 1% /app
/dev/sda1 283M 35M 233M 14% /boot
/dev/mapper/vg0-lv0 1.6G 1003M 461M 69% /mnt/lv0 #逻辑卷空间不足
2）VM虚拟机增加物理磁盘
3）在vmware虚拟机，新加硬盘不用重启的生效方法
[root@centos6 ~]#echo '- - -' >/sys/class/scsi_host/host0/scan #扫描添加磁盘（仅限vm使用）
[root@centos6 ~]#lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 100G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─vg0-lv1 (dm-1) 253:1 0 1.4G 0 lvm
└─sdb2 8:18 0 2G 0 part
├─vg0-lv0 (dm-0) 253:0 0 1.6G 0 lvm /mnt/lv0
└─vg0-lv1 (dm-1) 253:1 0 1.4G 0 lvm
sda 8:0 0 120G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 20G 0 part /
├─sda3 8:3 0 10G 0 part /app
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 4G 0 part [SWAP]
sr0 11:0 1 3.7G 0 rom
sdc 8:32 0 20G 0 disk
4）将新增物理磁盘修改成物理卷
[root@centos6 ~]#pvcreate /dev/sdc #创建物理卷
Physical volume "/dev/sdc" successfully created
5）扩展卷组（将新增加物理卷扩展到卷组）
[root@centos6 ~]#pvs #扩展卷组前查看物理卷情况
PV VG Fmt Attr PSize PFree
/dev/sdb1 vg0 lvm2 a--u 1.00g 0
/dev/sdb2 vg0 lvm2 a--u 2.00g 0
/dev/sdc lvm2 ---- 20.00g 20.00g #新增物理卷后面无VG名，表示没有扩展到vg卷组
[root@centos6 ~]#vgextend vg0 /dev/sdc #将新增加物理卷扩展到卷组（不能创建卷组）
Volume group "vg0" successfully extended
[root@centos6 ~]#pvs #查看物理卷
PV VG Fmt Attr PSize PFree
/dev/sdb1 vg0 lvm2 a--u 1.00g 0
/dev/sdb2 vg0 lvm2 a--u 2.00g 0
/dev/sdc vg0 lvm2 a--u 19.98g 19.98g #扩展卷组成功
[root@centos6 ~]#vgdisplay #查看卷组是否扩展成功
--- Volume group ---
VG Name vg0
System ID
Format lvm2
Metadata Areas 3
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 1
Max PV 0
Cur PV 3
Act PV 3
VG Size 22.98 GiB
PE Size 16.00 MiB
Total PE 1471
Alloc PE / Size 192 / 3.00 GiB
Free PE / Size 1279 / 19.98 GiB #Free PE空间扩展成功
VG UUID dpILvC-q23x-WCCH-Z1Or-SEH6-xdwS-Qope7b
6）扩展逻辑卷空间
[root@centos6 ~]#lvdisplay
--- Logical volume ---
LV Path /dev/vg0/lv0
LV Name lv0
VG Name vg0
LV UUID YTBvNy-3sg3-BBao-HOsf-d1uQ-oJVX-h6VKNb
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:04:15 +0800
LV Status available
# open 1
LV Size 1.56 GiB
Current LE 100 #逻辑卷的扩展盘区，表示100个LE大小
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Path /dev/vg0/lv1
LV Name lv1
VG Name vg0
LV UUID RM0Uss-17Di-yZnP-Rra6-pUvw-l3lT-EiHW5I
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:18:19 +0800
LV Status available
# open 0
LV Size 1.44 GiB
Current LE 92
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
[root@centos6 ~]#lvextend -L +5G /dev/vg0/lv0 #逻辑卷增加5G大小
Size of logical volume vg0/lv0 changed from 1.56 GiB (100 extents) to 6.56 GiB (420 extents).
Logical volume lv0 successfully resized.
[root@centos6 ~]#lvs #查看逻辑卷是否增加5G空间
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv0 vg0 -wi-ao---- 6.56g #lv0增加成功
lv1 vg0 -wi-a----- 1.44g
[root@centos6 ~]#df -h #查看逻辑卷的挂载点是否增加5G空间
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 20G 4.4G 15G 24% /
tmpfs 491M 72K 491M 1% /dev/shm
/dev/sda3 9.8G 23M 9.2G 1% /app
/dev/sda1 283M 35M 233M 14% /boot
/dev/mapper/vg0-lv0 1.6G 1003M 461M 69% /mnt/lv0 #逻辑卷挂载的目录没有增加5G
7）同步扩展空间的文件系统（不同步逻辑卷挂载点不能生效扩展的空间）
[root@centos6 ~]#resize2fs /dev/vg0/lv0 #同步逻辑卷扩展空间到挂载点的文件系统上
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/vg0/lv0 is mounted on /mnt/lv0; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 1
Performing an on-line resize of /dev/vg0/lv0 to 1720320 (4k) blocks.
The filesystem on /dev/vg0/lv0 is now 1720320 blocks long.
[root@centos6 ~]#df -h #查看逻辑卷挂载点扩展空间是否生效
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 20G 4.4G 15G 24% /
tmpfs 491M 72K 491M 1% /dev/shm
/dev/sda3 9.8G 23M 9.2G 1% /app
/dev/sda1 283M 35M 233M 14% /boot
/dev/mapper/vg0-lv0 6.5G 1004M 5.2G 17% /mnt/lv0 #扩展空间同步生效
[root@centos6 ~]#lvextend -r -l +100%FREE /dev/vg0/lv0 #扩展同时顺便同步文件系统
Size of logical volume vg0/lv0 changed from 6.56 GiB (420 extents) to 21.55 GiB (1379 extents).
Logical volume lv0 successfully resized.
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/vg0-lv0 is mounted on /mnt/lv0; on-line resizing required
old desc_blocks = 1, new_desc_blocks = 2
Performing an on-line resize of /dev/mapper/vg0-lv0 to 5648384 (4k) blocks.
The filesystem on /dev/mapper/vg0-lv0 is now 5648384 blocks long.
[root@centos6 ~]#df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 20G 4.4G 15G 24% /
tmpfs 491M 72K 491M 1% /dev/shm
/dev/sda3 9.8G 23M 9.2G 1% /app
/dev/sda1 283M 35M 233M 14% /boot
/dev/mapper/vg0-lv0 22G 1005M 20G 5% /mnt/lv0
[root@centos6 ~]#vgdisplay
--- Volume group ---
VG Name vg0
System ID
Format lvm2
Metadata Areas 3
Metadata Sequence No 6
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 1
Max PV 0
Cur PV 3
Act PV 3
VG Size 22.98 GiB
PE Size 16.00 MiB
Total PE 1471
Alloc PE / Size 1471 / 22.98 GiB
Free PE / Size 0 / 0 #空间为0
VG UUID dpILvC-q23x-WCCH-Z1Or-SEH6-xdwS-Qope7b
2、例子：缩减逻辑卷空间
1）先备份
2）取消挂载
[root@centos6 ~]#umount /mnt/lv0/
3）执行缩减文件系统
[root@centos6 ~]#resize2fs /dev/vg0/lv0 10G #直接执行缩减文件系统提示先执行检查
resize2fs 1.41.12 (17-May-2010)
Please run 'e2fsck -f /dev/vg0/lv0' first. #提示先检查逻辑卷
[root@centos6 ~]#fsck -f /dev/vg0/lv0 #检查逻辑卷
fsck from util-linux-ng 2.17.2
e2fsck 1.41.12 (17-May-2010)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/mapper/vg0-lv0: 13/1364624 files (7.7% non-contiguous), 350946/5648384 blocks
[root@centos6 ~]#resize2fs /dev/vg0/lv0 10G #再执行缩减文件系统
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/vg0/lv0 to 2621440 (4k) blocks.
The filesystem on /dev/vg0/lv0 is now 2621440 blocks long.
4）缩减逻辑卷空间
[root@centos6 ~]#lvreduce -L 10G /dev/vg0/lv0 #缩减逻辑卷空间
WARNING: Reducing active logical volume to 10.00 GiB.
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce vg0/lv0? [y/n]: y #你真想缩减逻辑卷？输入y表示同意
Size of logical volume vg0/lv0 changed from 21.55 GiB (1379 extents) to 10.00 GiB (640 extents).
Logical volume lv0 successfully resized.
5）重新挂载逻辑卷
[root@centos6 ~]#mount -a #重新挂载逻辑卷
[root@centos6 ~]#df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 20G 4.4G 15G 24% /
tmpfs 491M 72K 491M 1% /dev/shm
/dev/sda3 9.8G 23M 9.2G 1% /app
/dev/sda1 283M 35M 233M 14% /boot
/dev/mapper/vg0-lv0 9.9G 1004M 8.4G 11% /mnt/lv0 #逻辑卷空间和文件系统大小缩减10个G
例子：假设某块硬盘亮黄灯，快无法使用了，需要将此硬盘中的数据迁移到其他硬盘中
[root@centos6 ~]#pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 vg0 lvm2 a--u 1.00g 0
/dev/sdb2 vg0 lvm2 a--u 2.00g 0
/dev/sdc vg0 lvm2 a--u 19.98g 11.55g #/dev/sdc硬盘假设将要无法使用的硬盘
1）先检查坏硬盘中使用多少PE，再将这些PE迁移到同一个卷组中的其他成员中（物理卷），其他成员是否有足够空间来存放坏硬盘中的PE空间
[root@centos6 ~]#pvdisplay #查看物理卷可用空间
--- Physical volume ---
PV Name /dev/sdb1
VG Name vg0
PV Size 1.01 GiB / not usable 11.41 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 64
Free PE 0 #sdb1物理卷没有可用空间
Allocated PE 64
PV UUID EPcGil-E7Ng-08fP-FS1u-tzqR-MMtc-1kxX0k
--- Physical volume ---
PV Name /dev/sdb2
VG Name vg0
PV Size 2.01 GiB / not usable 7.19 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 128
Free PE 0 #sdb2没有可用空间
Allocated PE 128
PV UUID pqURc6-F7d9-nKmp-3KGi-rzdE-S9yD-Azm6s4
--- Physical volume ---
PV Name /dev/sdc #将要损坏的硬盘
VG Name vg0
PV Size 20.00 GiB / not usable 16.00 MiB
Allocatable yes
PE Size 16.00 MiB
Total PE 1279
Free PE 739
Allocated PE 540 #已使用540PE空间
PV UUID kxDllV-U4cE-zicK-GSx0-ELGm-0hLL-gV77ve
提示：显然/dev/sdb设备分区无法存放/dev/sdc中的PE空间，需要增加硬盘或/dev/sdb还可能再划分分区也可以。
[root@centos6 ~]#lsblk #查看sdb磁盘空间
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 100G 0 disk #sdb总大小100G，已用3G空间
├─sdb1 8:17 0 1G 0 part
│ └─vg0-lv1 (dm-1) 253:1 0 1.4G 0 lvm
└─sdb2 8:18 0 2G 0 part
├─vg0-lv0 (dm-0) 253:0 0 10G 0 lvm /mnt/lv0
└─vg0-lv1 (dm-1) 253:1 0 1.4G 0 lvm
sda 8:0 0 120G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 20G 0 part /
├─sda3 8:3 0 10G 0 part /app
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 4G 0 part [SWAP]
sr0 11:0 1 3.7G 0 rom
sdc 8:32 0 20G 0 disk
└─vg0-lv0 (dm-0) 253:0 0 10G 0 lvm /mnt/lv0
增加磁盘分区来存放坏硬盘占用PE空间
[root@centos6 ~]#fdisk /dev/sdb #划分分区
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p #创建主分区
Partition number (1-4): 3 #主分区号
First cylinder (395-13054, default 395): #保持默认
Using default value 395
Last cylinder, +cylinders or +size{K,M,G} (395-13054, default 13054): +20G #分配20G大小
Command (m for help): p #查看磁盘分区
Disk /dev/sdb: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x4074ebc8
Device Boot Start End Blocks Id System
/dev/sdb1 1 132 1060258+ 8e Linux LVM
/dev/sdb2 133 394 2104515 8e Linux LVM
/dev/sdb3 395 3006 20980890 83 Linux #需要修改分区ID，默认ID是83
Command (m for help): t #修改分区ID
Partition number (1-4): 3 #修改分区号
Hex code (type L to list codes): 8e #修改成8eID
Changed system type of partition 3 to 8e (Linux LVM) #将分区3系统类型修改成8e（Linux LVM）
Command (m for help): p
Disk /dev/sdb: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x4074ebc8
Device Boot Start End Blocks Id System
/dev/sdb1 1 132 1060258+ 8e Linux LVM
/dev/sdb2 133 394 2104515 8e Linux LVM
/dev/sdb3 395 3006 20980890 8e Linux LVM #修改完成
Command (m for help): w #最后保存
The partition table has been altered!
Calling ioctl() to re-read partition table.
WARNING: Re-reading the partition table failed with error 16: Device or resource busy.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8) #提示内核同步磁盘分区表失败，您可以重启或使用partprobe来同步磁盘分区表
Syncing disks.
[root@centos6 ~]#lsblk #查看sdb3分区是否同步
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 100G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─vg0-lv1 (dm-1) 253:1 0 1.4G 0 lvm
└─sdb2 8:18 0 2G 0 part
├─vg0-lv0 (dm-0) 253:0 0 10G 0 lvm /mnt/lv0
└─vg0-lv1 (dm-1) 253:1 0 1.4G 0 lvm
sda 8:0 0 120G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 20G 0 part /
├─sda3 8:3 0 10G 0 part /app
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 4G 0 part [SWAP]
sr0 11:0 1 3.7G 0 rom
sdc 8:32 0 20G 0 disk
└─vg0-lv0 (dm-0) 253:0 0 10G 0 lvm /mnt/lv0
[root@centos6 ~]#partx -a /dev/sdb #同步磁盘分区表到内核中
BLKPG: Device or resource busy
error adding partition 1
BLKPG: Device or resource busy
error adding partition 2
BLKPG: Device or resource busy
error adding partition 3
[root@centos6 ~]#lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 100G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─vg0-lv1 (dm-1) 253:1 0 1.4G 0 lvm
├─sdb2 8:18 0 2G 0 part
│ ├─vg0-lv0 (dm-0) 253:0 0 10G 0 lvm /mnt/lv0
│ └─vg0-lv1 (dm-1) 253:1 0 1.4G 0 lvm
└─sdb3 8:19 0 20G 0 part #同步分区表成功
sda 8:0 0 120G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 20G 0 part /
├─sda3 8:3 0 10G 0 part /app
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 4G 0 part [SWAP]
sr0 11:0 1 3.7G 0 rom
sdc 8:32 0 20G 0 disk
└─vg0-lv0 (dm-0) 253:0 0 10G 0 lvm /mnt/lv0
2）将新增分区加入物理卷中
[root@centos6 ~]#pvcreate /dev/sdb3 #/dev/sdb3加入物理卷
Physical volume "/dev/sdb3" successfully created
[root@centos6 ~]#pvs #查看是否加入物理卷
PV VG Fmt Attr PSize PFree
/dev/sdb1 vg0 lvm2 a--u 1.00g 0
/dev/sdb2 vg0 lvm2 a--u 2.00g 0
/dev/sdb3 lvm2 ---- 20.01g 20.01g #加入物理卷
/dev/sdc vg0 lvm2 a--u 19.98g 11.55g
3）将新增物理卷加入卷组中
[root@centos6 ~]#vgextend vg0 /dev/sdb3 #/dev/sdb3加入vg卷组中
Volume group "vg0" successfully extended
[root@centos6 ~]#vgdisplay #查看vg卷组空间大小
--- Volume group ---
VG Name vg0
System ID
Format lvm2
Metadata Areas 4
Metadata Sequence No 8
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 1
Max PV 0
Cur PV 4
Act PV 4
VG Size 42.98 GiB
PE Size 16.00 MiB
Total PE 2751
Alloc PE / Size 732 / 11.44 GiB
Free PE / Size 2019 / 31.55 GiB #vg中PE可用空间大小
VG UUID dpILvC-q23x-WCCH-Z1Or-SEH6-xdwS-Qope7b
[root@centos6 ~]#pvdisplay #查看物理卷
--- Physical volume ---
PV Name /dev/sdb1
VG Name vg0
PV Size 1.01 GiB / not usable 11.41 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 64
Free PE 0
Allocated PE 64
PV UUID EPcGil-E7Ng-08fP-FS1u-tzqR-MMtc-1kxX0k
--- Physical volume ---
PV Name /dev/sdb2
VG Name vg0
PV Size 2.01 GiB / not usable 7.19 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 128
Free PE 0
Allocated PE 128
PV UUID pqURc6-F7d9-nKmp-3KGi-rzdE-S9yD-Azm6s4
--- Physical volume ---
PV Name /dev/sdc #此时sdc硬盘PE空间可以迁移到同一卷组其他成员中
VG Name vg0
PV Size 20.00 GiB / not usable 16.00 MiB
Allocatable yes
PE Size 16.00 MiB
Total PE 1279
Free PE 739
Allocated PE 540
PV UUID kxDllV-U4cE-zicK-GSx0-ELGm-0hLL-gV77ve
--- Physical volume ---
PV Name /dev/sdb3
VG Name vg0
PV Size 20.01 GiB / not usable 9.15 MiB
Allocatable yes
PE Size 16.00 MiB
Total PE 1280
Free PE 1280
Allocated PE 0
PV UUID CqnVOx-CZFO-Hf6w-VyVh-KZmZ-buFr-KSYzj2
4）迁移坏硬盘已使用PE空间到同一卷组其他成员中
[root@centos6 ~]#pvmove /dev/sdc #迁移/dev/sdc已使用PE空间到同一卷组其他成员中
/dev/sdc: Moved: 0.2%
/dev/sdc: Moved: 100.0%
提示：pvmove自动检测坏硬盘已用PE空间迁移到哪个物理卷中，注意pvmove迁移的是PE空间不是数据，显然把PE空间移过去等于把数据迁移过去。
[root@centos6 ~]#pvdisplay #迁移后查看/dev/sdc的PE使用空间
--- Physical volume ---
PV Name /dev/sdb1
VG Name vg0
PV Size 1.01 GiB / not usable 11.41 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 64
Free PE 0
Allocated PE 64
PV UUID EPcGil-E7Ng-08fP-FS1u-tzqR-MMtc-1kxX0k
--- Physical volume ---
PV Name /dev/sdb2
VG Name vg0
PV Size 2.01 GiB / not usable 7.19 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 128
Free PE 0
Allocated PE 128
PV UUID pqURc6-F7d9-nKmp-3KGi-rzdE-S9yD-Azm6s4
--- Physical volume ---
PV Name /dev/sdc
VG Name vg0
PV Size 20.00 GiB / not usable 16.00 MiB
Allocatable yes
PE Size 16.00 MiB
Total PE 1279
Free PE 1279
Allocated PE 0 #PE使用空间为0，表示没有被逻辑卷占用
PV UUID kxDllV-U4cE-zicK-GSx0-ELGm-0hLL-gV77ve
--- Physical volume ---
PV Name /dev/sdb3
VG Name vg0
PV Size 20.01 GiB / not usable 9.15 MiB
Allocatable yes
PE Size 16.00 MiB
Total PE 1280
Free PE 740
Allocated PE 540
PV UUID CqnVOx-CZFO-Hf6w-VyVh-KZmZ-buFr-KSYzj2
5）删除VG中的/dev/sdc物理卷
[root@centos6 ~]#vgreduce vg0 /dev/sdc #删除vg0中的/dev/sdc物理卷
Removed "/dev/sdc" from volume group "vg0"
[root@centos6 ~]#pvdisplay #查看/dev/sdc是否被从vg0卷组中删除
--- Physical volume ---
PV Name /dev/sdb1
VG Name vg0
PV Size 1.01 GiB / not usable 11.41 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 64
Free PE 0
Allocated PE 64
PV UUID EPcGil-E7Ng-08fP-FS1u-tzqR-MMtc-1kxX0k
--- Physical volume ---
PV Name /dev/sdb2
VG Name vg0
PV Size 2.01 GiB / not usable 7.19 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 128
Free PE 0
Allocated PE 128
PV UUID pqURc6-F7d9-nKmp-3KGi-rzdE-S9yD-Azm6s4
--- Physical volume ---
PV Name /dev/sdb3
VG Name vg0
PV Size 20.01 GiB / not usable 9.15 MiB
Allocatable yes
PE Size 16.00 MiB
Total PE 1280
Free PE 740
Allocated PE 540
PV UUID CqnVOx-CZFO-Hf6w-VyVh-KZmZ-buFr-KSYzj2
"/dev/sdc" is a new physical volume of "20.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdc
VG Name #已被vg0卷组删除，此时变成独立物理卷
PV Size 20.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID kxDllV-U4cE-zicK-GSx0-ELGm-0hLL-gV77ve
6）从物理卷中删除/dev/sdc磁盘
[root@centos6 ~]#pvremove /dev/sdc #删除物理卷中的/dev/sdc物理卷
Labels on physical volume "/dev/sdc" successfully wiped
[root@centos6 ~]#pvs #dev/sdc物理卷被删除，变成普通磁盘
PV VG Fmt Attr PSize PFree
/dev/sdb1 vg0 lvm2 a--u 1.00g 0
/dev/sdb2 vg0 lvm2 a--u 2.00g 0
/dev/sdb3 vg0 lvm2 a--u 20.00g 11.56g
[root@centos6 ~]#lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdb 8:16 0 100G 0 disk
├─sdb1 8:17 0 1G 0 part
│ └─vg0-lv1 (dm-1) 253:1 0 1.4G 0 lvm
├─sdb2 8:18 0 2G 0 part
│ ├─vg0-lv0 (dm-0) 253:0 0 10G 0 lvm /mnt/lv0
│ └─vg0-lv1 (dm-1) 253:1 0 1.4G 0 lvm
└─sdb3 8:19 0 20G 0 part
└─vg0-lv0 (dm-0) 253:0 0 10G 0 lvm /mnt/lv0
sda 8:0 0 120G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 20G 0 part /
├─sda3 8:3 0 10G 0 part /app
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 4G 0 part [SWAP]
sr0 11:0 1 3.7G 0 rom
sdc 8:32 0 20G 0 disk #sdc变成普通磁盘
7）现在可以将此硬盘从服务器中拔出。
迁移准备前操作：
1）查看目标主机与源主机卷组及逻辑卷名称是否有重名（模拟此案例有重名）
[root@centos7 ~]#pvcreate /dev/sdb1 #目标主机创建物理卷
[root@centos7 ~]#vgcreate vg0 /dev/sdb1 #目标主机创建卷组
[root@centos7 ~]#lvcreate -n lv0 -l 100%FREE vg0 #目标主机创建逻辑卷
[root@centos7 ~]#mkfs.xfs /dev/vg0/lv0 #逻辑卷创建文件系统
[root@centos7 ~]#mkdir /mnt/lv0 #新建挂载点
[root@centos7 ~]#mount /dev/vg0/lv0 /mnt/lv0 #挂载逻辑卷
[root@centos7 ~]#lsblk #查看逻辑卷挂载情况
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 120G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 20G 0 part /
├─sda3 8:3 0 4G 0 part [SWAP]
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 10G 0 part /app
sdb 8:16 0 108G 0 disk
└─sdb1 8:17 0 2G 0 part
└─vg0-lv0 253:0 0 2G 0 lvm /mnt/lv0
sr0 11:0 1 8.8G 0 rom
1、源主机上操作
1）将centos6主机卷组迁移到centos7主机上，但是两个主机卷组及逻辑卷同名，需要先修改centos6主机卷组及逻辑卷名称
[root@centos6 ~]#vgrename vg0 centos6vg0 #修改Centos6主机上卷组名称
Volume group "vg0" successfully renamed to "centos6vg0"
[root@centos6 ~]#vgdisplay #查看修改后卷组名
--- Volume group ---
VG Name centos6vg0 #修改后卷组名
System ID
Format lvm2
Metadata Areas 3
Metadata Sequence No 13
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 1
Max PV 0
Cur PV 3
Act PV 3
VG Size 23.00 GiB
PE Size 16.00 MiB
Total PE 1472
Alloc PE / Size 732 / 11.44 GiB
Free PE / Size 740 / 11.56 GiB
VG UUID dpILvC-q23x-WCCH-Z1Or-SEH6-xdwS-Qope7b
修改逻辑卷名称
[root@centos6 ~]#lvrename /dev/centos6vg0/lv0 /dev/centos6vg0/centos6lv0 #修改逻辑卷名称
Renamed "lv0" to "centos6lv0" in volume group "centos6vg0"
[root@centos6 ~]#lvrename /dev/centos6vg0/lv1 /dev/centos6vg0/centos6lv1 #修改逻辑卷名称
Renamed "lv1" to "centos6lv1" in volume group "centos6vg0"
[root@centos6 ~]#lvdisplay #查看修改后的逻辑卷名称
--- Logical volume ---
LV Path /dev/centos6vg0/centos6lv0
LV Name centos6lv0 #修改后逻辑卷名称
VG Name centos6vg0
LV UUID YTBvNy-3sg3-BBao-HOsf-d1uQ-oJVX-h6VKNb
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:04:15 +0800
LV Status available
# open 1
LV Size 10.00 GiB
Current LE 640
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0
--- Logical volume ---
LV Path /dev/centos6vg0/centos6lv1
LV Name centos6lv1 #修改后的逻辑卷名称
VG Name centos6vg0
LV UUID RM0Uss-17Di-yZnP-Rra6-pUvw-l3lT-EiHW5I
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:18:19 +0800
LV Status available
# open 0
LV Size 1.44 GiB
Current LE 92
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1
2）取消逻辑卷挂载
[root@centos6 ~]#df -h #查看逻辑卷挂载情况
Filesystem Size Used Avail Use% Mounted on
/dev/sda2 20G 4.4G 15G 24% /
tmpfs 491M 72K 491M 1% /dev/shm
/dev/sda3 9.8G 23M 9.2G 1% /app
/dev/sda1 283M 35M 233M 14% /boot
/dev/mapper/vg0-lv0 9.9G 1004M 8.4G 11% /mnt/lv0
[root@centos6 ~]#umount /mnt/lv0 #取消逻辑卷挂载
3）停用卷组
[root@centos6 ~]#vgchange -an centos6vg0 #禁用卷组
0 logical volume(s) in volume group "centos6vg0" now active
[root@centos6 ~]#lvdisplay #查看逻辑卷状态
--- Logical volume ---
LV Path /dev/centos6vg0/centos6lv0
LV Name centos6lv0
VG Name centos6vg0
LV UUID YTBvNy-3sg3-BBao-HOsf-d1uQ-oJVX-h6VKNb
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:04:15 +0800
LV Status NOT available #lv状态无法使用
LV Size 10.00 GiB
Current LE 640
Segments 2
Allocation inherit
Read ahead sectors auto
--- Logical volume ---
LV Path /dev/centos6vg0/centos6lv1
LV Name centos6lv1
VG Name centos6vg0
LV UUID RM0Uss-17Di-yZnP-Rra6-pUvw-l3lT-EiHW5I
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:18:19 +0800
LV Status NOT available #lv状态无法使用
LV Size 1.44 GiB
Current LE 92
Segments 2
Allocation inherit
Read ahead sectors auto
4）导出卷组
[root@centos6 ~]#vgexport centos6vg0 #导出卷组
Volume group "centos6vg0" successfully exported
[root@centos6 ~]#vgdisplay #查看卷组状态
--- Volume group ---
VG Name centos6vg0
System ID
Format lvm2
Metadata Areas 3
Metadata Sequence No 16
VG Access read/write
VG Status exported/resizable #卷组状态为导出状态
MAX LV 0
Cur LV 2
Open LV 0
Max PV 0
Cur PV 3
Act PV 3
VG Size 23.00 GiB
PE Size 16.00 MiB
Total PE 1472
Alloc PE / Size 732 / 11.44 GiB
Free PE / Size 740 / 11.56 GiB
VG UUID dpILvC-q23x-WCCH-Z1Or-SEH6-xdwS-Qope7b
[root@centos6 ~]#pvdisplay #查看物理卷中卷组状态
Physical volume "/dev/sdb1" of volume group "centos6vg0" is exported
--- Physical volume ---
PV Name /dev/sdb1
VG Name centos6vg0 (exported) #卷组显示导出状态
PV Size 1.01 GiB / not usable 11.41 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 64
Free PE 0
Allocated PE 64
PV UUID EPcGil-E7Ng-08fP-FS1u-tzqR-MMtc-1kxX0k
Physical volume "/dev/sdb2" of volume group "centos6vg0" is exported
--- Physical volume ---
PV Name /dev/sdb2
VG Name centos6vg0 (exported) #卷组显示导出状态
PV Size 2.01 GiB / not usable 7.19 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 128
Free PE 0
Allocated PE 128
PV UUID pqURc6-F7d9-nKmp-3KGi-rzdE-S9yD-Azm6s4
Physical volume "/dev/sdb3" of volume group "centos6vg0" is exported
--- Physical volume ---
PV Name /dev/sdb3
VG Name centos6vg0 (exported) #卷组显示导出状态
PV Size 20.01 GiB / not usable 9.15 MiB
Allocatable yes
PE Size 16.00 MiB
Total PE 1280
Free PE 740
Allocated PE 540
PV UUID CqnVOx-CZFO-Hf6w-VyVh-KZmZ-buFr-KSYzj2
5）Centos6关机拔出sdb硬盘（该环境在VM上做实验，所以关机拔硬盘；真正服务器支持热挺拔硬盘）
在目标主机上操作
6）查找出Centos6中卷组所在硬盘，拔出硬盘安装到Centos7主机上
7）在VM虚拟Centos7上添加Centos6主机上的硬盘(添加过程省略)
8）查看Centos7是否添加硬盘成功
[root@centos7 ~]#lsblk #添加硬盘没有同步
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 120G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 20G 0 part /
├─sda3 8:3 0 4G 0 part [SWAP]
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 10G 0 part /app
sdb 8:16 0 108G 0 disk
└─sdb1 8:17 0 2G 0 part
└─vg0-lv0 253:0 0 2G 0 lvm /mnt/lv0
sr0 11:0 1 8.8G 0 rom
[root@centos7 ~]#echo '- - -' >/sys/class/scsi_host/host2/scan #同步分区表（此命令仅限VM使用）
[root@centos7 ~]#lsblk #查看硬盘是否添加成功
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 120G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 20G 0 part /
├─sda3 8:3 0 4G 0 part [SWAP]
├─sda4 8:4 0 1K 0 part
└─sda5 8:5 0 10G 0 part /app
sdb 8:16 0 108G 0 disk
└─sdb1 8:17 0 2G 0 part
└─vg0-lv0 253:0 0 2G 0 lvm /mnt/lv0
sdc 8:32 0 100G 0 disk #centos6硬盘添加成功
├─sdc1 8:33 0 1G 0 part
├─sdc2 8:34 0 2G 0 part
└─sdc3 8:35 0 20G 0 part
sr0 11:0 1 8.8G 0 rom
9）还原卷组导入状态
[root@centos7 ~]#pvdisplay #查看新添加硬盘中物理卷状态
Physical volume "/dev/sdc1" of volume group "centos6vg0" is exported
--- Physical volume ---
PV Name /dev/sdc1
VG Name centos6vg0 (exported) #VG状态还是导出状态
PV Size 1.01 GiB / not usable <11.41 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 64
Free PE 0
Allocated PE 64
PV UUID EPcGil-E7Ng-08fP-FS1u-tzqR-MMtc-1kxX0k
Physical volume "/dev/sdc2" of volume group "centos6vg0" is exported
--- Physical volume ---
PV Name /dev/sdc2
VG Name centos6vg0 (exported) #VG状态还是导出状态
PV Size <2.01 GiB / not usable 7.19 MiB
Allocatable yes (but full)
PE Size 16.00 MiB
Total PE 128
Free PE 0
Allocated PE 128
PV UUID pqURc6-F7d9-nKmp-3KGi-rzdE-S9yD-Azm6s4
Physical volume "/dev/sdc3" of volume group "centos6vg0" is exported
--- Physical volume ---
PV Name /dev/sdc3
VG Name centos6vg0 (exported) #VG状态还是导出状态
PV Size <20.01 GiB / not usable 9.15 MiB
Allocatable yes
PE Size 16.00 MiB
Total PE 1280
Free PE 740
Allocated PE 540
PV UUID CqnVOx-CZFO-Hf6w-VyVh-KZmZ-buFr-KSYzj2
--- Physical volume ---
PV Name /dev/sdb1
VG Name vg0
PV Size 2.00 GiB / not usable 4.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 511
Free PE 0
Allocated PE 511
PV UUID csidmP-Bwzd-1xnY-YO0d-hnCw-TocR-Fu5PLp
[root@centos7 ~]#vgimport centos6vg0 #还原centos6卷组为导入状态
Volume group "centos6vg0" successfully imported
[root@centos7 ~]#vgdisplay #查看新添加硬盘中的卷组状态
--- Volume group ---
VG Name centos6vg0
System ID
Format lvm2
Metadata Areas 3
Metadata Sequence No 17
VG Access read/write
VG Status resizable #VG卷组状态已还原
MAX LV 0
Cur LV 2
Open LV 0
Max PV 0
Cur PV 3
Act PV 3
VG Size 23.00 GiB
PE Size 16.00 MiB
Total PE 1472
Alloc PE / Size 732 / <11.44 GiB
Free PE / Size 740 / 11.56 GiB
VG UUID dpILvC-q23x-WCCH-Z1Or-SEH6-xdwS-Qope7b
--- Volume group ---
VG Name vg0
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 2
VG Access read/write
VG Status resizable #VG卷组状态已还原
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 1
Act PV 1
VG Size <2.00 GiB
PE Size 4.00 MiB
Total PE 511
Alloc PE / Size 511 / <2.00 GiB
Free PE / Size 0 / 0
VG UUID 395Vaf-BYr2-8yoc-UudL-N8Qk-vely-qmH40D
[root@centos7 ~]#lvdisplay #查看添加硬盘中的逻辑卷状态
--- Logical volume ---
LV Path /dev/centos6vg0/centos6lv0
LV Name centos6lv0
VG Name centos6vg0
LV UUID YTBvNy-3sg3-BBao-HOsf-d1uQ-oJVX-h6VKNb
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:04:15 +0800
LV Status NOT available #lv状态为无法使用
LV Size 10.00 GiB
Current LE 640
Segments 2
Allocation inherit
Read ahead sectors auto
--- Logical volume ---
LV Path /dev/centos6vg0/centos6lv1
LV Name centos6lv1
VG Name centos6vg0
LV UUID RM0Uss-17Di-yZnP-Rra6-pUvw-l3lT-EiHW5I
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:18:19 +0800
LV Status NOT available #lv状态为无法使用
LV Size <1.44 GiB
Current LE 92
Segments 2
Allocation inherit
Read ahead sectors auto
--- Logical volume ---
LV Path /dev/vg0/lv0
LV Name lv0
VG Name vg0
LV UUID Mdt9CZ-kyd6-vjs5-davl-bbtC-TIiR-uDP6tg
LV Write Access read/write
LV Creation host, time centos7.magedu.com, 2018-06-09 14:43:10 +0800
LV Status available
# open 1
LV Size <2.00 GiB
Current LE 511
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
10）激活centos6vg0卷组，且逻辑卷也被激活
[root@centos7 ~]#vgchange -ay centos6vg0 #激活卷组
2 logical volume(s) in volume group "centos6vg0" now active
[root@centos7 ~]#lvdisplay #查看逻辑卷状态
--- Logical volume ---
LV Path /dev/centos6vg0/centos6lv0
LV Name centos6lv0
VG Name centos6vg0
LV UUID YTBvNy-3sg3-BBao-HOsf-d1uQ-oJVX-h6VKNb
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:04:15 +0800
LV Status available #状态为可用
# open 0
LV Size 10.00 GiB
Current LE 640
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:1
--- Logical volume ---
LV Path /dev/centos6vg0/centos6lv1
LV Name centos6lv1
VG Name centos6vg0
LV UUID RM0Uss-17Di-yZnP-Rra6-pUvw-l3lT-EiHW5I
LV Write Access read/write
LV Creation host, time centos6.magedu.com, 2018-06-08 19:18:19 +0800
LV Status available #状态为可用
# open 0
LV Size <1.44 GiB
Current LE 92
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:2
--- Logical volume ---
LV Path /dev/vg0/lv0
LV Name lv0
VG Name vg0
LV UUID Mdt9CZ-kyd6-vjs5-davl-bbtC-TIiR-uDP6tg
LV Write Access read/write
LV Creation host, time centos7.magedu.com, 2018-06-09 14:43:10 +0800
LV Status available
# open 1
LV Size <2.00 GiB
Current LE 511
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0
11）挂载逻辑卷
[root@centos7 ~]#mkdir /mnt/centos6lv0 #创建挂载点
[root@centos7 ~]#mount /dev/centos6vg0/centos6lv0 /mnt/centos6lv0/ #挂载逻辑卷到挂载点上
[root@centos7 ~]#ls /mnt/centos6lv0/ #查看挂载点内容
f1 f2 lost+found
原文地址：http://blog.51cto.com/2067926/2126821
