例如想扩展 / 分区

[root@mysql mapper]# df -h
Filesystem                    Size  Used Avail Use% Mounted on
/dev/mapper/vg_mysql-lv_root   24G  8.4G   14G  39% /
tmpfs                         499M  224K  498M   1% /dev/shm
/dev/sda1                     485M   35M  426M   8% /boot
[root@mysql mapper]#fdik -l  查看可用的磁盘

添加逻辑卷

[root@mysql mapper]# fdisk /dev/sdb

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):n

Command action
   l   logical (5 or over)
   p   primary partition (1-4)
l
First cylinder (1961-2610, default 1961):
Using default value 1961
Last cylinder, +cylinders or +size{K,M,G} (1961-2610, default 2610):
Using default value 2610

Command (m for help):w 保存

[root@mysql mapper]# fdisk -l

Disk /dev/sda: 10.7 GB, 10737418240 bytes
255 heads, 63 sectors/track, 1305 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: 0x000b6c05

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        1306     9972736   8e  Linux LVM

Disk /dev/sdb: 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: 0x3eb0062a

Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1        2610    20964793+   5  Extended
/dev/sdb5               1        1306    10490382   83  Linux
/dev/sdb6            1307        1960     5253223+  83  Linux
/dev/sdb7            1961        2610     5221093+  83  Linux ----- 新增逻辑卷

[root@mysql mapper]# partx -a /dev/sdb7
[root@mysql mapper]# pvcreate /dev/sdb7  创建PV

[root@mysql mapper]# vgs    查看你需要扩展的VG
  VG       #PV #LV #SN Attr   VSize  VFree
  vg_mysql   3   2   0 wz--n- 24.52g 8.00m
[root@mysql mapper]#vgextend vg_mysql /dev/sdb6 扩展VG

[root@mysql mapper]#lvextend -L +5G /dev/mapper/vg_mysql-lv_root 扩展LV
[root@mysql mapper]#resize2fs /dev/mapper/vg_mysql-lv_root  重置vg大小