服务器使用的是阿里云的服务器，由于原来阿里云还不支持磁盘直接扩容，所以当时做了lvm卷组管理，以便后期磁盘不足时可以灵活的扩展，以下是我目前的环境：
[Qoocoadmin@iZ25noqnry1Z ~]$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/xvda1 20G 2.0G 17G 11% /
tmpfs 1.9G 0 1.9G 0% /dev/shm
/dev/mapper/VolGroup-data
936G 820G 69G 93% /data
如上，磁盘已快不足了，在阿里云的控制台将磁盘扩展到1500GB，然后在控制台重启服务器（在系统中重启无效），重启前先将 /etc/fstab 中的磁盘挂载信息注释掉。
[root@iZ25noqnry1Z ~]# cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Thu Jul 3 10:43:14 2014
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=2a348234-4a73-491c-98e9-47900d88697b / ext4 defaults,barrier=0 1 1
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
none /proc/xen xenfs defaults 0 0
#/dev/VolGroup/data /data ext4 defaults 0 0
重启后ssh登录系统，如下：
[root@iZ25noqnry1Z ~]# fdisk -l
Disk /dev/xvda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 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: 0x00060953
Device Boot Start End Blocks Id System
/dev/xvda1 * 1 2611 20970496 83 Linux
Disk /dev/xvdb: 1610.6 GB, 1610612736000 bytes
255 heads, 63 sectors/track, 195812 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: 0xe3ad639b
Device Boot Start End Blocks Id System
/dev/xvdb1 1 130541 1048570551 8e Linux LVM
Disk /dev/mapper/VolGroup-data: 1020.1 GB, 1020054732800 bytes
255 heads, 63 sectors/track, 124014 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: 0x00000000
如上，磁盘扩容已生效。
接下来进行lvm扩容。
1. 将扩展的磁盘进行分区
[root@iZ25noqnry1Z ~]# fdisk /dev/xvdb
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): p
Disk /dev/xvdb: 1610.6 GB, 1610612736000 bytes
255 heads, 63 sectors/track, 195812 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: 0xe3ad639b
Device Boot Start End Blocks Id System
/dev/xvdb1 1 130541 1048570551 8e Linux LVM
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 2
First cylinder (130542-195812, default 130542):
Using default value 130542
Last cylinder, +cylinders or +size{K,M,G} (130542-195812, default 195812):
Using default value 195812
Command (m for help): p
Disk /dev/xvdb: 1610.6 GB, 1610612736000 bytes
255 heads, 63 sectors/track, 195812 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: 0xe3ad639b
Device Boot Start End Blocks Id System
/dev/xvdb1 1 130541 1048570551 8e Linux LVM
/dev/xvdb2 130542 195812 524289307+ 83 Linux
Command (m for help): t
Partition number (1-4): 2
Hex code (type L to list codes): 8e
Changed system type of partition 2 to 8e (Linux LVM)
Command (m for help): p
Disk /dev/xvdb: 1610.6 GB, 1610612736000 bytes
255 heads, 63 sectors/track, 195812 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: 0xe3ad639b
Device Boot Start End Blocks Id System
/dev/xvdb1 1 130541 1048570551 8e Linux LVM
/dev/xvdb2 130542 195812 524289307+ 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: 设备或资源忙.
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.
出现上面信息，root重启一下服务器。
重启后查看磁盘信息，如下：
[root@iZ25noqnry1Z ~]# fdisk -l
Disk /dev/xvda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 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: 0x00060953
Device Boot Start End Blocks Id System
/dev/xvda1 * 1 2611 20970496 83 Linux
Disk /dev/xvdb: 1610.6 GB, 1610612736000 bytes
255 heads, 63 sectors/track, 195812 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: 0xe3ad639b
Device Boot Start End Blocks Id System
/dev/xvdb1 1 130541 1048570551 8e Linux LVM
/dev/xvdb2 130542 195812 524289307+ 8e Linux LVM
Disk /dev/mapper/VolGroup-data: 1020.1 GB, 1020054732800 bytes
255 heads, 63 sectors/track, 124014 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: 0x00000000
2. 创建PV物理卷
[root@iZ25noqnry1Z ~]# pvcreate /dev/xvdb2
Physical volume "/dev/xvdb2" successfully created
3. 将pv加入现有的vg组中
[root@iZ25noqnry1Z ~]# vgextend VolGroup /dev/xvdb2
Volume group "VolGroup" successfully extended
4. 扩展现有lv卷
[root@iZ25noqnry1Z ~]# lvextend -L +327200 /dev/VolGroup/data
Extending logical volume data to 1.24 TiB
Logical volume data successfully resized
5. 刷新容量
[root@iZ25noqnry1Z ~]# lvextend -L +327200 /dev/VolGroup/data
Extending logical volume data to 1.24 TiB
Logical volume data successfully resized
[root@iZ25noqnry1Z ~]# resize2fs /dev/VolGroup/data
resize2fs 1.41.12 (17-May-2010)
请先运行 'e2fsck -f /dev/VolGroup/data'.
出现以上，那就执行一下吧。
[root@iZ25noqnry1Z ~]# e2fsck -f /dev/VolGroup/data
e2fsck 1.41.12 (17-May-2010)
第一步: 检查inode,块,和大小
第二步: 检查目录结构
第3步: 检查目录连接性
/lost+found未找到.创建<y>? 是
Pass 4: Checking reference counts
第5步: 检查簇概要信息
/dev/VolGroup/data: ***** 文件系统已修改 *****
/dev/VolGroup/data: 173081/62259200 files (1.8% non-contiguous), 218725658/249036800 blocks
[root@iZ25noqnry1Z ~]#
执行检查完成，再次执行刷新：
[root@iZ25noqnry1Z ~]# resize2fs /dev/VolGroup/data
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/VolGroup/data to 332800000 (4k) blocks.
The filesystem on /dev/VolGroup/data is now 332800000 blocks long.
6. 挂载磁盘
[root@iZ25noqnry1Z data]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/xvda1 20G 1.9G 17G 11% /
tmpfs 1.9G 0 1.9G 0% /dev/shm
/dev/mapper/VolGroup-data
1.3T 820G 367G 70% /data
7. 将 /etc/fstab 文件中注释的磁盘挂载信息打开，可以重启一下服务器看是否依然正常挂载，成功挂载就OK了。