版本：VirtualBox 5.0.14
之前VirtualBox创建的虚拟机的vdi文件过小，无法满足新的实验需求，扩容vdi文件的方法如下：
比如我这里将RHEL6_Primary12cRAC2.vdi文件扩容到60000M大小，方法如下：
VBoxManage modifyhd E:\Vbox\Primary12cRAC2\RHEL6_Primary12cRAC2.vdi –resize 60000
实际执行过程：
c:\Program Files\Oracle\VirtualBox>VBoxManage modifyhd E:\Vbox\Primary12cRAC2\RH
EL6_Primary12cRAC2.vdi --resize 60000
0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%
至此虚拟机层面的操作就算完成了。
但是这个时候启动虚拟机会发现大小没有变化：
[root@jydb2 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_linuxbase-lv_root 28G 2.0G 24G 8% /
tmpfs 3.9G 0 3.9G 0% /dev/shm
/dev/sda1 485M 39M 421M 9% /boot
实际上这是因为我这里的环境使用的lvm，而对应的根分区使用的是磁盘的一个分区，而扩容的vdi对应的是/dev/sda磁盘,下面继续来看详细情况：
[root@jydb2 ~]# fdisk -l /dev/sda
Disk /dev/sda: 62.9 GB, 62914560000 bytes
255 heads, 63 sectors/track, 7648 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: 0x00047a24
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 3917 30944256 8e Linux LVM
可以看到/dev/sda已经成功扩容，现在只需要把扩容的空间新建成一个分区：
[root@jydb2 ~]# 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): p
Disk /dev/sda: 62.9 GB, 62914560000 bytes
255 heads, 63 sectors/track, 7648 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: 0x00047a24
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 3917 30944256 8e Linux LVM
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (3917-7648, default 3917):
Using default value 3917
Last cylinder, +cylinders or +size{K,M,G} (3917-7648, default 7648):
Using default value 7648
Command (m for help): p
Disk /dev/sda: 62.9 GB, 62914560000 bytes
255 heads, 63 sectors/track, 7648 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: 0x00047a24
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 3917 30944256 8e Linux LVM
/dev/sda3 3917 7648 29975280 83 Linux
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.
[root@jydb2 ~]# partprobe
Warning: WARNING: the kernel failed to re-read the partition table on /dev/sda (Device or resource busy). As a result, it may not reflect all of your changes until after reboot.
新加的分区需要重启才能生效。
重启虚拟机之后就可以将新加的分区创建成pv加入到vg,最终扩容lv即可，可以分为4个步骤，具体如下:
1.创建pv
[root@jydb2 ~]# pvcreate /dev/sda3
Physical volume "/dev/sda3" successfully created
[root@jydb2 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 vg_linuxbase lvm2 a-- 29.51g 0
/dev/sda3 lvm2 a-- 28.59g 28.59g
2.扩容vg
[root@jydb2 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
vg_linuxbase 1 2 0 wz--n- 29.51g 0
[root@jydb2 ~]# vgextend -h
vgextend: Add physical volumes to a volume group
vgextend
[-A|--autobackup y|n]
[--restoremissing]
[-d|--debug]
[-f|--force]
[-h|--help]
[-t|--test]
[-v|--verbose]
[--version]
[-y|--yes]
[ PHYSICAL DEVICE OPTIONS ]
VolumeGroupName PhysicalDevicePath [PhysicalDevicePath...]
[root@jydb2 ~]# vgextend vg_linuxbase /dev/sda3
Volume group "vg_linuxbase" successfully extended
[root@jydb2 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
vg_linuxbase 2 2 0 wz--n- 58.09g 28.58g
3.扩容lv
[root@jydb2 ~]# lvs
LV VG Attr LSize Pool Origin Data% Move Log Cpy%Sync Convert
lv_root vg_linuxbase -wi-ao---- 27.54g
lv_swap vg_linuxbase -wi-ao---- 1.97g
[root@jydb2 ~]# vgdisplay
--- Volume group ---
VG Name vg_linuxbase
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 58.09 GiB
PE Size 4.00 MiB
Total PE 14871
Alloc PE / Size 7821 / 30.55 GiB
Free PE / Size 7050 / 27.54 GiB
VG UUID 41Wk3c-fuD0-SKcX-RqNQ-7uIP-e2xD-1mWaUd
[root@jydb2 ~]# lvresize -l +7050 /dev/mapper/vg_linuxbase-lv_root
Extending logical volume lv_root to 56.12 GiB
Logical volume lv_root successfully resized
[root@jydb2 ~]# vgdisplay
--- Volume group ---
VG Name vg_linuxbase
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 6
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 58.09 GiB
PE Size 4.00 MiB
Total PE 14871
Alloc PE / Size 14871 / 58.09 GiB
Free PE / Size 0 / 0
VG UUID 41Wk3c-fuD0-SKcX-RqNQ-7uIP-e2xD-1mWaUd
[root@jydb2 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_linuxbase-lv_root 29G 2.0G 25G 8% /
tmpfs 3.9G 0 3.9G 0% /dev/shm
/dev/sda1 485M 39M 421M 9% /boot
4.resize2fs lv
[root@jydb2 ~]# resize2fs /dev/mapper/vg_linuxbase-lv_root
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/vg_linuxbase-lv_root is mounted on /; on-line resizing required
old desc_blocks = 2, new_desc_blocks = 4
Performing an on-line resize of /dev/mapper/vg_linuxbase-lv_root to 14711808 (4k) blocks.
The filesystem on /dev/mapper/vg_linuxbase-lv_root is now 14711808 blocks long.
[root@jydb2 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_linuxbase-lv_root 56G 2.0G 51G 4% /
tmpfs 3.9G 0 3.9G 0% /dev/shm
/dev/sda1 485M 39M 421M 9% /boot
至此，已成功扩容了该虚拟机的系统根目录。
