废话不多说，这里直接举例说明：

[root@Mysql01-213-66 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_mysql0121366-LogVol02 7.7G 2.6G 4.8G 36% /
tmpfs 495M 0 495M 0% /dev/shm
/dev/sda1 194M 29M 155M 16% /boot
/dev/mapper/vg_mysql0121366-LogVol01 8.0G 3.1G 5.0G 38% /data
这里增加/data大小

[root@Mysql01-213-66 ~]# fdisk -l /dev/sda

Disk /dev/sda: 40.8 GB, 40802189312 bytes
255 heads, 63 sectors/track, 4960 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: 0x000eb81f

Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 2350 18668544 8e Linux LVM

进行分区
[root@Mysql01-213-66 ~]# fdisk /dev/sda

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
Partition number (1-4): 3
First cylinder (2350-4960, default 2350):
Using default value 2350
Last cylinder, +cylinders or +size{K,M,G} (2350-4960, default 4960):
Using default value 4960

Command (m for help): p

Disk /dev/sda: 40.8 GB, 40802189312 bytes
255 heads, 63 sectors/track, 4960 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: 0x000eb81f

Device Boot Start End Blocks Id System
/dev/sda1 * 1 26 204800 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 26 2350 18668544 8e Linux LVM
/dev/sda3 2350 4960 20966832 83 Linux

Command (m for help): t
Partition number (1-4): 3
Hex code (type L to list codes): 8e
Changed system type of partition 3 to 8e (Linux LVM)

Command (m for help): w
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)
Syncing disks.

重启服务器或者　partprobe
创建物理卷
[root@Mysql01-213-66 ~]# pvcreate /dev/sda3
Physical volume "/dev/sda3" successfully created
使用vgscan查询物理卷
[root@Mysql01-213-66 ~]# vgscan
Reading all physical volumes. This may take a while...
Found volume group "vg_mysql0121366" using metadata type lvm2
使用新增物理卷扩展vg
[root@Mysql01-213-66 ~]# vgextend vg_mysql0121366 /dev/sda3
Volume group "vg_mysql0121366" successfully extended
[root@Mysql01-213-66 ~]# vgscan
Reading all physical volumes. This may take a while...
Found volume group "vg_mysql0121366" using metadata type lvm2
查询vg
[root@Mysql01-213-66 ~]# vgdisplay
--- Volume group ---
VG Name vg_mysql0121366
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 5
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 2
Act PV 2
VG Size 37.79 GiB
PE Size 4.00 MiB
Total PE 9675
Alloc PE / Size 4557 / 17.80 GiB
Free PE / Size 5118 / 19.99 GiB
VG UUID Zy2PVv-xSsx-NEAv-L6ba-G8Oy-tBBq-5zXKQm
查询lv
[root@Mysql01-213-66 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/vg_mysql0121366/LogVol01
LV Name LogVol01
VG Name vg_mysql0121366
LV UUID 5znkJ2-wdeZ-Y2o1-ECDS-gzzl-PqaS-qo2yZR
LV Write Access read/write
LV Creation host, time Mysql01-213-66, 2015-08-30 20:42:13 +0800
LV Status available
# open 1
LV Size 8.00 GiB
Current LE 2048
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2

--- Logical volume ---
LV Path /dev/vg_mysql0121366/LogVol00
LV Name LogVol00
VG Name vg_mysql0121366
LV UUID b1FV1n-iKyK-kZ23-glRO-opFh-gDRp-TzWNcL
LV Write Access read/write
LV Creation host, time Mysql01-213-66, 2015-08-30 20:42:14 +0800
LV Status available
# open 1
LV Size 2.00 GiB
Current LE 512
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:0

--- Logical volume ---
LV Path /dev/vg_mysql0121366/LogVol02
LV Name LogVol02
VG Name vg_mysql0121366
LV UUID eoVdk3-cbcP-9PlI-kZBL-6pY2-Jpbl-1WI2uH
LV Write Access read/write
LV Creation host, time Mysql01-213-66, 2015-08-30 20:42:14 +0800
LV Status available
# open 1
LV Size 7.80 GiB
Current LE 1997
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:1

[root@Mysql01-213-66 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_mysql0121366-LogVol02 7.7G 2.6G 4.8G 35% /
tmpfs 495M 0 495M 0% /dev/shm
/dev/sda1 194M 29M 155M 16% /boot
/dev/mapper/vg_mysql0121366-LogVol01 8.0G 3.1G 5.0G 38% /data
扩展lv
[root@Mysql01-213-66 ~]# lvextend -L +19G /dev/mapper/vg_mysql0121366-LogVol01
Extending logical volume LogVol01 to 27.00 GiB
Logical volume LogVol01 successfully resized
[root@Mysql01-213-66 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_mysql0121366-LogVol02 7.7G 2.6G 4.8G 35% /
tmpfs 495M 0 495M 0% /dev/shm
/dev/sda1 194M 29M 155M 16% /boot
/dev/mapper/vg_mysql0121366-LogVol01 8.0G 3.1G 5.0G 38% /data
若不是xfs我们可以用resize2fs，这里报错了
[root@Mysql01-213-66 ~]# resize2fs -f /dev/mapper/vg_mysql0121366-LogVol01
resize2fs 1.41.12 (17-May-2010)
resize2fs: Bad magic number in super-block while trying to open /dev/mapper/vg_mysql0121366-LogVol01
Couldn‘t find valid filesystem superblock.
[root@Mysql01-213-66 ~]# xfs_growfs /dev/mapper/vg_mysql0121366-LogVol01
meta-data=http://www.mamicode.com/dev/mapper/vg_mysql0121366-LogVol01 isize=256 agcount=4, agsize=524288 blks
= sectsz=512 attr=2, projid32bit=0
data = http://www.mamicode.com/bsize=4096 blocks=2097152, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0
log =internal bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 2097152 to 7077888
[root@Mysql01-213-66 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_mysql0121366-LogVol02 7.7G 2.6G 4.8G 35% /
tmpfs 495M 0 495M 0% /dev/shm
/dev/sda1 194M 29M 155M 16% /boot
/dev/mapper/vg_mysql0121366-LogVol01 27G 3.1G 24G 12% /data

LVM 扩容报错：resize2fs: Bad magic number in super-block while......