详解Centos7扩展磁盘空间（LVM管理）

# fdisk -l /dev/sda
Disk /dev/sda: 21.5 GB, 21474836480 bytes, 41943040 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x00063fa6

  Device Boot   Start     End   Blocks  Id System
/dev/sda1  *    2048   1026047   512000  83 Linux
/dev/sda2     1026048  20971519   9972736  8e Linux LVM
/dev/sda3    20971520  41943039  10485760  8e Linux LVM

# df -h
Filesystem        Size Used Avail Use% Mounted on
/dev/mapper/centos-root  19G 8.1G  11G 44% /
devtmpfs         482M   0 482M  0% /dev
tmpfs          497M  88K 497M  1% /dev/shm
tmpfs          497M 7.0M 490M  2% /run
tmpfs          497M   0 497M  0% /sys/fs/cgroup
/dev/sda1        497M 157M 341M 32% /boot
Share          103G  36G  67G 35% /media/sf_Share
tmpfs          100M 4.0K 100M  1% /run/user/42
tmpfs          100M  12K 100M  1% /run/user/0

# dd if=/dev/zero of=1.0G.img bs=1M count=1000
dd: writing `1.0G.img': No space left on device
1+0 records in
0+0 records out
8192 bytes (8.2 kB) copied, 0.00300509 s, 2.7 MB/s

# fdisk /dev/sda
n {new partition}
p {primary partition}
3 {partition number}
[这时会提示修改大小，选择默认直接回车即可]
t {change partition id}
3 {partition number}
8e {Linux LVM partition}
w

# vgdisplay
 --- Volume group ---
 VG Name        centos
 System ID       
 Format        lvm2

#pvcreate /dev/sda3

# vgextend centos /dev/sda3
 No physical volume label read from /dev/sda3
 Writing physical volume data to disk "/dev/sda3"
 Physical volume "/dev/sda3" successfully created
 Volume group "vg_aimin" successfully extended

# lvdisplay
 --- Logical volume ---
 LV Path        /dev/centos/root
 LV Name        root
 VG Name        centos

# lvextend /dev/centos/root /dev/sda3

# xfs_growfs /dev/centos/root

# lvscan
 ACTIVE      '/dev/centos/root' [18.46 GiB] inherit
 ACTIVE      '/dev/centos/swap' [1.00 GiB] inherit