查看挂载根目录是否为逻辑卷（系统默认挂载根目录方式：逻辑卷）
[[email protected] cloudera-manager]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_hadoop2-lv_root
18G 17G 0 100% /
tmpfs 932M 4.0K 932M 1% /dev/shm
/dev/sda1 477M 42M 411M 10% /boot
如果是 /dev/mapper/... 表示逻辑卷，/dev/sda*:直接挂载物理盘
步骤：
1.在虚拟机关机的情况下，点击需要扩容的虚拟机设置
点击右下角扩展：填写的数字需要比现在的磁盘大小要大；
2.开启虚拟机，查看磁盘大小 与扩容前大小不一致说明扩容成功
[[email protected] ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 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: 0x0001f66e
Device Boot Start End Blocks Id System
/dev/sda1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 64 2611 20458496 8e Linux LVM
/dev/sda3 2611 3916 10483750 83 Linux
3.使用fdisk /dev/sda, 创建新分区。
注意：不同操作系统的磁盘命名方式不同，有些是/dev/sda。具体使用方式参考第三步中fdisk -l首行显示Disk。如笔者在该系统中首行显示为Disk /dev/sda: 53.7 GB, 53687091200 bytes ，故使用命令fdisk /dev/sda）
[[email protected] ~]# 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): m --查看所有命令
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help): n --新建分区
Command action
e extended
p primary partition (1-4)
p --创建独立分区
Selected partition 4
First cylinder (3917-6527, default 3917): --回车默认
Using default value 3917
Last cylinder, +cylinders or +size{K,M,G} (3917-6527, default 6527): --回车默认
Using default value 6527
Command (m for help): t --改变分区编号
Partition number (1-4): 4 --不要和已有的编号重复
Hex code (type L to list codes): 8e --分区的类型
Changed system type of partition 4 to 8e (Linux LVM)
Command (m for help): p --显示分区信息
Disk /dev/sda: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 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: 0x0001f66e
Device Boot Start End Blocks Id System
/dev/sda1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 64 2611 20458496 8e Linux LVM
/dev/sda3 2611 3916 10483750 83 Linux
/dev/sda4 3917 6527 20972857+ 8e Linux LVM
Command (m for help): w ---保存信息
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.4.reboot命令重启虚拟机查看分区，多了sda4
[[email protected] ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes
255 heads, 63 sectors/track, 6527 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: 0x0001f66e
Device Boot Start End Blocks Id System
/dev/sda1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 64 2611 20458496 8e Linux LVM
/dev/sda3 2611 3916 10483750 83 Linux
/dev/sda4 3917 6527 20972857+ 8e Linux LVM正式开始扩容
1. pvcreate命令 用于将物理硬盘分区初始化为物理卷，以便LVM使用。
#pvcreate /dev/sda4 --分区为新增分区名称
[[email protected] ~]# pvcreate /dev/sda4
Physical volume "/dev/sda4" successfully created查看新建的物理卷和大小
[[email protected] ~]# vgdisplay
--- Volume group ---
VG Name vg_hadoop2
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 5
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 2
Act PV 2
VG Size 29.50 GiB
PE Size 4.00 MiB
Total PE 7553
Alloc PE / Size 7553 / 29.50 GiB
Free PE / Size 0 / 0
VG UUID MVOZ8z-qRjX-csiA-X4hI-JXwD-Wph1-E6sScZ
2.vgextend命令 用于动态扩展LVM卷组，它通过向卷组中添加物理卷来增加卷组的容量。LVM卷组中的物理卷可以在使用
# vgextend vg_hadoop2 /dev/sda4 -- 填写查询的物理卷名称 新增分区
[[email protected] ~]# vgextend vg_hadoop2 /dev/sda4
Volume group "vg_hadoop2" successfully extended3. 增加lv_root的大小，增加20G
# lvextend -L +20G /dev/mapper/vg_hadoop2-lv_root
[[email protected] ~]# lvextend -L +20G /dev/mapper/vg_hadoop2-lv_root
Size of logical volume vg_hadoop2/lv_root changed from 27.50 GiB (7041 extents) to 47.50 GiB (12161 extents).
Logical volume lv_root successfully resized.
4. 重新识别大小， xfs_qrowfs 是centos7的命令，在centos6.X中是resize2fs
# resize2fs /dev/mapper/vg_hadoop2-lv_root
[email protected] ~]# resize2fs /dev/mapper/vg_hadoop2-lv_root
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/vg_hadoop2-lv_root is mounted on /; on-line resizing required
old desc_blocks = 2, new_desc_blocks = 3
Performing an on-line resize of /dev/mapper/vg_hadoop2-lv_root to 12452864 (4k) blocks.
The filesystem on /dev/mapper/vg_hadoop2-lv_root is now 12452864 blocks long.
5. 查看扩容后的大小
[[email protected] ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_hadoop2-lv_root
47G 23G 23G 50% /
tmpfs 932M 80K 932M 1% /dev/shm
/dev/sda1 477M 42M 411M 10% /boot
/dev/sr0 3.7G 3.7G 0 100% /media/CentOS_6.9_Final
参考博客：
https://blog.csdn.net/max229max/article/details/80356250