操作步骤简述：
1.查看磁盘信息
2.给硬盘/dev/sdc添加分区/dev/sdc1
2.1.fdisk /dev/sdc
m 查看帮助
n 添加新分区
t 修改分区类型为：8e Linux LVM
p 查看分区
w 写入分区表并退出
q 不保存分区表并退出
3.扩展逻辑卷/dev/mapper/vg_RedHat-lv_root的大小
3.1进入LVM管理器
3.2将物理卷添加到现有卷组（也可直接将分区添加到现有卷组）
3.3查看所有逻辑卷
3.4扩展逻辑卷大小
实际操作过程：
[root@TEST ~]# df -hl
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_redhat-lv_root 45G 36G 6.7G 85% /
tmpfs 7.8G 3.8G 4.1G 48% /dev/shm
/dev/sda1 485M 39M 421M 9% /boot
[root@TEST ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes
64 heads, 32 sectors/track, 51200 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000af440
Device Boot Start End Blocks Id System
/dev/sda1 * 2 501 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 502 51200 51915776 8e Linux LVM
Partition 2 does not end on cylinder boundary.
Disk /dev/sdb: 17.2 GB, 17179869184 bytes
64 heads, 32 sectors/track, 16384 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdc: 42.9 GB, 42949672960 bytes
64 heads, 32 sectors/track, 40960 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/mapper/vg_redhat-lv_root: 49.0 GB, 48997859328 bytes
255 heads, 63 sectors/track, 5956 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: 0x00000000
Disk /dev/mapper/vg_redhat-lv_swap: 4160 MB, 4160749568 bytes
255 heads, 63 sectors/track, 505 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: 0x00000000
[root@TEST ~]# fdisk /dev/sdc
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x93ae6d58.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
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
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-40960, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-40960, default 40960): +40G
Value out of range.
Last cylinder, +cylinders or +size{K,M,G} (1-40960, default 40960): +39G
Command (m for help): t
Selected partition 1
Hex code (type L to list codes): L
0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris
1 FAT12 39 Plan 9 82 Linux swap / So c1 DRDOS/sec (FAT-
2 XENIX root 3c PartitionMagic 83 Linux c4 DRDOS/sec (FAT-
3 XENIX usr 40 Venix 80286 84 OS/2 hidden C: c6 DRDOS/sec (FAT-
4 FAT16 <32M 41 PPC PReP Boot 85 Linux extended c7 Syrinx
5 Extended 42 SFS 86 NTFS volume set da Non-FS data
6 FAT16 4d QNX4.x 87 NTFS volume set db CP/M / CTOS / .
7 HPFS/NTFS 4e QNX4.x 2nd part 88 Linux plaintext de Dell Utility
8 AIX 4f QNX4.x 3rd part 8e Linux LVM df BootIt
9 AIX bootable 50 OnTrack DM 93 Amoeba e1 DOS access
a OS/2 Boot Manag 51 OnTrack DM6 Aux 94 Amoeba BBT e3 DOS R/O
b W95 FAT32 52 CP/M 9f BSD/OS e4 SpeedStor
c W95 FAT32 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi eb BeOS fs
e W95 FAT16 (LBA) 54 OnTrackDM6 a5 FreeBSD ee GPT
f W95 Ext'd (LBA) 55 EZ-Drive a6 OpenBSD ef EFI (FAT-12/16/
10 OPUS 56 Golden Bow a7 NeXTSTEP f0 Linux/PA-RISC b
11 Hidden FAT12 5c Priam Edisk a8 Darwin UFS f1 SpeedStor
12 Compaq diagnost 61 SpeedStor a9 NetBSD f4 SpeedStor
14 Hidden FAT16 <3 63 GNU HURD or Sys ab Darwin boot f2 DOS secondary
16 Hidden FAT16 64 Novell Netware af HFS / HFS+ fb VMware VMFS
17 Hidden HPFS/NTF 65 Novell Netware b7 BSDI fs fc VMware VMKCORE
18 AST SmartSleep 70 DiskSecure Mult b8 BSDI swap fd Linux raid auto
1b Hidden W95 FAT3 75 PC/IX bb Boot Wizard hid fe LANstep
1c Hidden W95 FAT3 80 Old Minix be Solaris boot ff BBT
1e Hidden W95 FAT1
Hex code (type L to list codes): 8e
Changed system type of partition 1 to 8e (Linux LVM)
Command (m for help): p
Disk /dev/sdc: 42.9 GB, 42949672960 bytes
64 heads, 32 sectors/track, 40960 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x93ae6d58
Device Boot Start End Blocks Id System
/dev/sdc1 1 39937 40895472 8e Linux LVM
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@TEST ~]# fdisk -l
Disk /dev/sda: 53.7 GB, 53687091200 bytes
64 heads, 32 sectors/track, 51200 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000af440
Device Boot Start End Blocks Id System
/dev/sda1 * 2 501 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2 502 51200 51915776 8e Linux LVM
Partition 2 does not end on cylinder boundary.
Disk /dev/sdb: 17.2 GB, 17179869184 bytes
64 heads, 32 sectors/track, 16384 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/sdc: 42.9 GB, 42949672960 bytes
64 heads, 32 sectors/track, 40960 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x93ae6d58
Device Boot Start End Blocks Id System
/dev/sdc1 1 39937 40895472 8e Linux LVM
Disk /dev/mapper/vg_redhat-lv_root: 49.0 GB, 48997859328 bytes
255 heads, 63 sectors/track, 5956 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: 0x00000000
Disk /dev/mapper/vg_redhat-lv_swap: 4160 MB, 4160749568 bytes
255 heads, 63 sectors/track, 505 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: 0x00000000
[root@TEST ~]# lvm
lvm> pvcreate /dev/sdc1
Physical volume "/dev/sdc1" successfully created
lvm> pvremove /dev/sdc1
Labels on physical volume "/dev/sdc1" successfully wiped
lvm> vgextend vg_redhat /dev/sdc1 【不知道vg名字可以在root下执行vgdisplay查看】
No physical volume label read from /dev/sdc1
Physical volume /dev/sdc1 not found
Physical volume "/dev/sdc1" successfully created
Volume group "vg_redhat" successfully extended
lvm> lvextend -L +39G /dev/mapper/vg_redhat-lv_root
Extending logical volume lv_root to 84.63 GiB
Insufficient free space: 9984 extents needed, but only 9983 available
lvm> lvextend -L +38.99G /dev/mapper/vg_redhat-lv_root
Rounding size to boundary between physical extents: 38.99 GiB
Extending logical volume lv_root to 84.62 GiB
Logical volume lv_root successfully resized
lvm> pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name vg_redhat
PV Size 49.51 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 12674
Free PE 0
Allocated PE 12674
PV UUID ILOutm-u1Gf-chRB-rhn4-RGVg-hcEb-mN02Fm
--- Physical volume ---
PV Name /dev/sdc1
VG Name vg_redhat
PV Size 39.00 GiB / not usable 4.98 MiB
Allocatable yes
PE Size 4.00 MiB
Total PE 9983
Free PE 9983
Allocated PE 0
PV UUID nrqQ7M-PCVI-cDAy-ufew-WYYv-8HPF-dRyraa
lvm> quit
Exiting.
[root@TEST ~]# resize2fs /dev/mapper/vg_redhat-lv_root
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/vg_redhat-lv_root is mounted on /; on-line resizing required
old desc_blocks = 3, new_desc_blocks = 6
Performing an on-line resize of /dev/mapper/vg_redhat-lv_root to 22183936 (4k) blocks.
The filesystem on /dev/mapper/vg_redhat-lv_root is now 22183936 blocks long.