擴容之前的磁盤狀況
[root@localhost ~]# df -h
文件系統 容量 已用 可用已用%%掛載點
/dev/mapper/VolGroup-lv_root 5.3G 2.5G 2.6G 50% /
tmpfs 538M 0 538M 0% /dev/shm
/dev/sda1 485M 30M 430M 7% /boot
[root@localhost ~]# fdisk -l
Disk /dev/sda: 8589 MB, 8589934592 bytes
...............
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 1045 7875584 8e Linux LVM
Disk /dev/mapper/VolGroup-lv_root: 5779 MB, 5779750912 bytes
........
Disk /dev/mapper/VolGroup-lv_swap: 2281 MB, 2281701376 bytes
.........
此次擴容的方案為：
1、加1個5G的空間給/
2、加1個10G的空間給/Oracle
（一） 在VM中加一個15G的磁盤
重啟後#fdisk –l可以看到新的磁盤已經認出來了。
Disk /dev/sdb: 16.1 GB, 16106127360 bytes
............................
Disk /dev/sdb doesn't contain a valid partition table
（二）創建物理卷(PV)
pvcreate /dev/sdb
查看系統PV的情況：
[root@localhost ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2 //原有硬盤上的PV
VG Name VolGroup
PV Size 7.51 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 1922
Free PE 0
Allocated PE 1922
PV UUID SGH1dY-4tp2-Nr1a-w93Z-V4LA-pQBh-VGzzTH
"/dev/sdb" is a new physical volume of "15.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb
VG Name //新建的PV的VG name是空的，下一步就是把PV加入VG
PV Size 15.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID 8TZUlz-YyUp-RBvf-lSzm-7MgG-DSZS-qNqX1Z
查看原VG的情況
[root@localhost ~]# vgdisplay
--- Volume group ---
VG Name VolGroup //注意記錄此名字，擴容時將新的pv加入指定的名字
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size 7.51 GiB
PE Size 4.00 MiB
Total PE 1922
AllocPE / Size 1922 / 7.51 GiB
Free PE / Size 0 / 0
VG UUID FnUsmX-s284-GeRK-hJNJ-BbIG-Vpe7-OuFZE1
