[root@CentOS6 ~]# fdisk -l /dev/sdb
Disk /dev/sdb: 85.9 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 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: 0x77136fd1
Device Boot Start End Blocks Id System
/dev/sdb1 1 1306 10490413+ 8e Linux LVM
/dev/sdb2 1307 2351 8393962+ 8e Linux LVM
/dev/sdb3 2352 3005 5253255 8e Linux LVM
/dev/sdb4 3006 10443 59745735 5 Extended
/dev/sdb5 3006 3789 6297448+ 8e Linux LVM
2）然后创建pv：pvcreate [-f] /dev/sdb{1,2,3,5}
[root@CentOS6 ~]# pvcreate /dev/sdb{1,2,3,5}
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdb2" successfully created
Physical volume "/dev/sdb3" successfully created
Physical volume "/dev/sdb5" successfully created
3）查看PV信息：pvdisplay [/dev/sdb{1,2,3,5}]
# 因为是刚刚创建的，所以还不属于任何卷组，所以没有信息状态
[root@CentOS6 ~]# pvdisplay /dev/sdb1
"/dev/sdb1" is a new physical volume of "10.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size 10.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID ZNXE1y-rOAW-ket1-Wlzl-Tckl-NqD7-v4lUYb
2.创建卷组 VG
★与VG相关的管理命令
7.LVM 逻辑卷管理
1)显示卷组
vgs：显示简要信息；
vgdisplay：显示详细信息；
2)创建卷组
vgcreate [-s #[kKmMgGtTpPeE] [卷组名] [物理设备]
3)管理卷组
vgextend：扩展卷组，在VG内添加额外的PV；
vgreduce：缩减卷组
4)删除卷组
先做pvmove，再做 vgremove
创建步骤
1.新增一个vg，并指明其包含哪个或哪些pv实现；
[root@CentOS6 ~]# vgcreate myvg /dev/sdb1
Volume group "myvg" successfully created
2.查看vg信息及包含的pv信息
[root@CentOS6 ~]# vgdisplay myvg
--- Volume group ---
VG Name myvg
System ID
Format lvm2
Metadata Areas 1
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 1
Act PV 1
VG Size 10.00 GiB
PE Size 4.00 MiB
Total PE 2560
Alloc PE / Size 0 / 0
Free PE / Size 2560 / 10.00 GiB
VG UUID DhKq9c-esRV-0uKq-AQlV-mrWx-A6de-41frUH
# 查看PV 的信息，可以看到之前创建PV 有信息了
[root@CentOS6 ~]# pvdisplay /dev/sdb1
--- Physical volume ---
PV Name /dev/sdb1
VG Name myvg
PV Size 10.00 GiB / not usable 4.54 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 2560
Free PE 2560
Allocated PE 0
PV UUID ZNXE1y-rOAW-ket1-Wlzl-Tckl-NqD7-v4lUYb
3.如果想增加VG的容量，进行如下操作： vgextend [卷组名] [pv名]
[root@CentOS6 ~]# vgextend myvg /dev/sdb2
Volume group "myvg" successfully extended
[root@CentOS6 ~]# vgdisplay myvg
--- Volume group ---
VG Name myvg
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 2
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 18.00 GiB
PE Size 4.00 MiB
Total PE 4609
Alloc PE / Size 0 / 0
Free PE / Size 4609 / 18.00 GiB # 由原来的10G变为18G，为/dev/sdb1与/dev/sdb2之和
VG UUID DhKq9c-esRV-0uKq-AQlV-mrWx-A6de-41frUH
[root@CentOS6 ~]# pvdisplay /dev/sdb2
--- Physical volume ---
PV Name /dev/sdb2
VG Name myvg
PV Size 8.01 GiB / not usable 1.23 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 2049
Free PE 2049
Allocated PE 0
PV UUID QqoawY-wc0c-hv7E-gyuJ-KVXw-d5yu-7tfw5e
4.如果要想把指定pv从卷组中移除，进行如下操作：
首先，用pvmove命令把要移除pv中的数据转移到其他pv中
然后，执行 vgreduce 命令，移除指定pv
# 注意：要从VG中移除pv之前，一定要把该PV中的数据移除到其他PV中，并确保其他PV中能够容纳
# 这些数据。因为这里是刚刚创建的所以显示没有数据，可直接从VG中移除
[root@CentOS6 ~]# pvmove /dev/sdb2
No data to move for myvg
[root@CentOS6 ~]# vgreduce myvg /dev/sdb2
Removed "/dev/sdb2" from volume group "myvg"
[root@CentOS6 ~]# vgdisplay myvg
--- Volume group ---
VG Name myvg
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 1
Act PV 1
VG Size 10.00 GiB # 移除成功，发现VG 变小了
PE Size 4.00 MiB
Total PE 2560
Alloc PE / Size 0 / 0
Free PE / Size 2560 / 10.00 GiB
VG UUID DhKq9c-esRV-0uKq-AQlV-mrWx-A6de-41frUH
[root@CentOS6 ~]# mkfs.ext4 -L MYLV -b 1024 /dev/mapper/myvg-mylv
mke2fs 1.41.12 (17-May-2010)
Filesystem label=MYLV
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
131072 inodes, 2097152 blocks
104857 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=69206016
256 block groups
8192 blocks per group, 8192 fragments per group
512 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409, 663553,
1024001, 1990657
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 38 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
3.挂载
# 查看设备属性信息
[root@CentOS6 ~]# blkid /dev/mapper/myvg-mylv
/dev/mapper/myvg-mylv: LABEL="MYLV" UUID="7be26849-b0e5-43f5-87ab-ae46511c306c" TYPE="ext4"
# 创建挂载点
[root@CentOS6 ~]# mkdir /testdir
# 挂载，这里注意文件路径，两者都可以
[root@CentOS6 ~]# mount /dev/myvg/mylv /testdir
[root@CentOS6 ~]# mount
/dev/mapper/vg0-root on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw)
/dev/sda1 on /boot type ext4 (rw)
/dev/mapper/vg0-usr on /usr type ext4 (rw)
/dev/mapper/vg0-var on /var type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/dev/mapper/myvg-mylv on /testdir type ext4 (rw) # 挂载成功
[root@CentOS6 testdir]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg0-root 20G 1.9G 17G 11% /
tmpfs 491M 0 491M 0% /dev/shm
/dev/sda1 190M 34M 147M 19% /boot
/dev/mapper/vg0-usr 9.8G 2.1G 7.2G 23% /usr
/dev/mapper/vg0-var 20G 471M 19G 3% /var
/dev/mapper/myvg-mylv
2.0G 3.1M 1.9G 1% /testdir # 挂载成功，大小为2G
# 可以正常使用
[root@CentOS6 ~]# cd /testdir/
[root@CentOS6 testdir]# ls
lost+found
[root@CentOS6 testdir]# cp /etc/fstab ./
[root@CentOS6 testdir]# ls
fstab lost+found
扩展和缩减逻辑卷
1.扩展逻辑卷
★管理命令：
☉扩展物理便捷
# lvextend -L [+]#[mMgGtT] /dev/VG_NAME/LV_NAME
☉扩展文件系统逻辑边界
# resize2fs /dev/VG_NAME/LV_NAME（只适用于ext系列的文件系统）
# 直接扩展逻辑卷到5G，也可以使用 +3G
[root@CentOS6 testdir]# lvextend -L 5G /dev/myvg/mylv
Size of logical volume myvg/mylv changed from 2.00 GiB (512 extents) to 5.00 GiB (1280 extents).
Logical volume mylv successfully resized.
[root@CentOS6 testdir]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg0-root 20G 1.9G 17G 11% /
tmpfs 491M 0 491M 0% /dev/shm
/dev/sda1 190M 34M 147M 19% /boot
/dev/mapper/vg0-usr 9.8G 2.1G 7.2G 23% /usr
/dev/mapper/vg0-var 20G 471M 19G 3% /var
/dev/mapper/myvg-mylv
2.0G 3.1M 1.9G 1% /testdir
# 发现还是之前的2G，这时因为扩展的只是物理可用空间，但物理可用空间上文件系统的可用空间
# 并没有随之扩展，还是创建文件系统时的大小，要想让文件系统也随之扩展到5G，就要使用resize2fs命令
[root@CentOS6 testdir]# resize2fs /dev/myvg/mylv # resize2fs后没有跟大小，就意味着扩展到可用的最大物理空间
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/myvg/mylv is mounted on /testdir; on-line resizing required
old desc_blocks = 8, new_desc_blocks = 20
Performing an on-line resize of /dev/myvg/mylv to 5242880 (1k) blocks.
The filesystem on /dev/myvg/mylv is now 5242880 blocks long.
[root@CentOS6 testdir]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg0-root 20G 1.9G 17G 11% /
tmpfs 491M 0 491M 0% /dev/shm
/dev/sda1 190M 34M 147M 19% /boot
/dev/mapper/vg0-usr 9.8G 2.1G 7.2G 23% /usr
/dev/mapper/vg0-var 20G 471M 19G 3% /var
/dev/mapper/myvg-mylv
4.9G 3.4M 4.7G 1% /testdir # 变为5G
[root@CentOS6 ~]# resize2fs /dev/myvg/mylv 3G
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/myvg/mylv to 3145728 (1k) blocks.
The filesystem on /dev/myvg/mylv is now 3145728 blocks long.
3.缩减物理边界到指定大小
[root@CentOS6 ~]# lvreduce -L 3G /dev/myvg/mylv
WARNING: Reducing active logical volume to 3.00 GiB.
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce myvg/mylv? [y/n]: y
Size of logical volume myvg/mylv changed from 5.00 GiB (1280 extents) to 3.00 GiB (768 extents).
Logical volume mylv successfully resized.
