演示针对LVM分区的管理
假设已经增加一块磁盘：/dev/sdb
一、将sdb配置成LVM分区
1）当前系统有sda和sdb2个物理磁盘，各有100G的大小。
[root@svr200-11 ~]# ls /dev/sd*
sda sda1 sda2 sdb
2）给sdb分区
[root@svr200-11 ~]# 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‘).
注1：使用“n”创建新分区
Command (m for help): n
Command action
e extended
p primary partition (1-4)
注2：使用“p”创建主分区
p
注3：使用“1”创建分区1（在1-4中选择，当前磁盘支持最多4个主分区，GPT格式的磁盘支持更多主分区）
Partition number (1-4): 1
注4：选择默认值
First cylinder (1-13054, default 1):
Using default value 1
注5：选择一个分区大小，看提示，可以用"+|大小|单位"这样的格式，此处是增加20G的分区
Last cylinder, +cylinders or +size{K,M,G} (1-13054, default 13054): +20G
注6：更改分区格式为LVM，先输入“t”，然后输入“8e”（Linux LVM），不清楚请输入“l”去查看对应的代码
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)
注7：打印当前的分区状态
Command (m for help): p
Disk /dev/sdb: 107.4 GB, 107374182400 bytes
255 heads, 63 sectors/track, 13054 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: 0xb07a7c89
Device Boot Start End Blocks Id System
/dev/sdb1 1 2612 20980858+ 8e Linux LVM
注8：确认无误，写入磁盘
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
二、物理卷（Physical Volume）
1）创建PV
[root@svr200-11 ~]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created
2）查看PV
[root@svr200-11 ~]# pvdisplay
--- Physical volume ---
PV Name /dev/sda2
VG Name vg_svr20011
PV Size 99.51 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 25474
Free PE 0
Allocated PE 25474
PV UUID e6qCiB-18zU-r31G-DT4S-1NRY-rl1e-tEtODx
"/dev/sdb1" is a new physical volume of "20.01 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size 20.01 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID KGaTzb-M5YB-gQ10-evlf-Ww81-eSYH-92g0Hr
三、卷组（Volume Group）
1）创建一个VG，定义组名，组员（PV）
[root@svr200-11 ~]# vgcreate vg_test01 /dev/sdb1
Volume group "vg_test01" successfully created
2）查看VG
[root@svr200-11 ~]# vgdisplay
--- Volume group ---
VG Name vg_test01
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 1
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 0
Open LV 0
Max PV 0
Cur PV 1
Act PV 1
VG Size 20.01 GiB
PE Size 4.00 MiB
Total PE 5122
Alloc PE / Size 0 / 0
Free PE / Size 5122 / 20.01 GiB
VG UUID 4dSqWG-WLin-if3X-GrdV-ccc0-SxrS-6Nxzn6
--- Volume group ---
VG Name vg_svr20011
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 4
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 3
Open LV 3
Max PV 0
Cur PV 1
Act PV 1
VG Size 99.51 GiB
PE Size 4.00 MiB
Total PE 25474
Alloc PE / Size 25474 / 99.51 GiB
Free PE / Size 0 / 0
VG UUID dFGxMZ-L0ir-irYV-Vrzq-2fqW-N1Wg-Q620BH
四、逻辑卷（Logical Volume）
1）创建一个新LV（理解成常规的一个分区，需要mkfs格式化后挂载到文件系统使用），定义大小，逻辑卷名称，以及从哪个VG上创建。
[root@svr200-11 ~]# lvcreate -L 8G -n lv_test01 vg_test01
Logical volume "lv_test01" created
2）查看逻辑卷
[root@svr200-11 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/vg_test01/lv_test01
LV Name lv_test01
VG Name vg_test01
LV UUID odJa0V-3eC0-0Ggh-fh7J-7QAf-tJ3Q-MS3e9L
LV Write Access read/write
LV Creation host, time svr200-11, 2015-04-30 12:05:58 +0800
LV Status available
# open 0
LV Size 8.00 GiB
Current LE 2048
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:3
--- Logical volume ---
（忽略其他LV的信息）
五、格式化lv并挂载到文件系统使用
1）格式化
[root@svr200-11 ~]# mkfs -t ext4 /dev/vg_test01/lv_test01
（输出略）
2）挂载
[root@svr200-11 ~]# mkdir /data/test01
[root@svr200-11 ~]# mount /dev/vg_test01/lv_test01 /data/test01/
[root@svr200-11 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_svr20011-lv_root 50G 3.1G 44G 7% /
tmpfs 499M 0 499M 0% /dev/shm
/dev/sda1 485M 34M 426M 8% /boot
/dev/mapper/vg_svr20011-lv_home 47G 38G 7.2G 84% /home
/dev/mapper/vg_test01-lv_test01 7.9G 146M 7.4G 2% /data/test01
注：当然了，也要记得更新fstab文件
六、当前状态
1）物理磁盘：sdb，100G
2）新建了一个LVM格式的分区：sdb1，20G
3）新建了一个vg（vg_test01），把sdb1加入了vg_test01中
4）在vg_test01上，创建了一个大小为8G的分区lv_test01（逻辑卷lv）
5）格式化和挂载分区lv_test01到/data/test01上使用
七、上述是常规的增加一个分区的步骤，接下来探讨如何给分区扩容。
假设已经删除了上面使用的/dev/sdb，这次的目的是，给卷组（vg_svr20011）扩容，最终是要给逻辑卷（lv_home）扩容
扫描和删除有如下命令：
pvscan
vgscan
lvscan
pvremove
vgremove
lvremove
1）创建/dev/sdb1，大小全部空间（100G），LVM分区
fdisk /dev/sdb <<_EOF
n
p
1
t
8e
p
w
_EOF
创建PV：
[root@svr200-11 ~]# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created
查看PV状态：
[root@svr200-11 ~]# pvscan
PV /dev/sda2 VG vg_svr20011 lvm2 [99.51 GiB / 0 free]
PV /dev/sdb1 lvm2 [100.00 GiB]
Total: 2 [199.51 GiB] / in use: 1 [99.51 GiB] / in no VG: 1 [100.00 GiB]
给现有的VG扩容：
[root@svr200-11 ~]# vgextend vg_svr20011 /dev/sdb1
Volume group "vg_svr20011" successfully extended
再次查看PV的状态：
[root@svr200-11 ~]# pvscan
PV /dev/sda2 VG vg_svr20011 lvm2 [99.51 GiB / 0 free]
PV /dev/sdb1 VG vg_svr20011 lvm2 [100.00 GiB / 100.00 GiB free]
Total: 2 [199.50 GiB] / in use: 2 [199.50 GiB] / in no VG: 0 [0 ]
sdb1已经和sda2已经属于同一个卷组。
2）给逻辑卷（LV）扩容
查看LV的状态：
[root@svr200-11 ~]# lvscan
ACTIVE ‘/dev/vg_svr20011/lv_root‘ [50.00 GiB] inherit
ACTIVE ‘/dev/vg_svr20011/lv_home‘ [47.54 GiB] inherit
ACTIVE ‘/dev/vg_svr20011/lv_swap‘ [1.97 GiB] inherit
目前lv_home 使用了50G，先扩容到80G看看
[root@svr200-11 ~]# lvextend -L 80G /dev/vg_svr20011/lv_home
Extending logical volume lv_home to 80.00 GiB
Logical volume lv_home successfully resized
[root@svr200-11 ~]# lvscan
ACTIVE ‘/dev/vg_svr20011/lv_root‘ [50.00 GiB] inherit
ACTIVE ‘/dev/vg_svr20011/lv_home‘ [80.00 GiB] inherit
ACTIVE ‘/dev/vg_svr20011/lv_swap‘ [1.97 GiB] inherit
用df查看分区信息：
[root@svr200-11 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_svr20011-lv_root 50G 3.1G 44G 7% /
tmpfs 499M 0 499M 0% /dev/shm
/dev/sda1 485M 34M 426M 8% /boot
/dev/mapper/vg_svr20011-lv_home 47G 38G 7.2G 84% /home
此时用df命令查看分区，会发现分区大小尚未更新，因为我们还需要on-line resize一下分区：
[root@svr200-11 ~]# resize2fs /dev/vg_svr20011/lv_home
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/vg_svr20011/lv_home is mounted on /home; on-line resizing required
old desc_blocks = 3, new_desc_blocks = 5
Performing an on-line resize of /dev/vg_svr20011/lv_home to 20971520 (4k) blocks.
The filesystem on /dev/vg_svr20011/lv_home is now 20971520 blocks long.
再看：
[root@svr200-11 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_svr20011-lv_root 50G 3.1G 44G 7% /
tmpfs 499M 0 499M 0% /dev/shm
/dev/sda1 485M 34M 426M 8% /boot
/dev/mapper/vg_svr20011-lv_home 79G 38G 38G 50% /home
符合预期
八、附上一个可有可无的小脚本，用于快速的删除和建立lvm分区来熟悉命令
[root@svr200-11 ~]# cat lvm_fdisk.sh
#!/bin/bash
#
# 2015/4/30
# 创建和删除lvm分区的一个示例
function part_lvm() {
echo -e "\033[1;40;31m[+] 使用fdisk创建分区\033[0m"
echo -e "\033[40;32m开始操作：\033[40;37m"
fdisk $1 <<_EOF
n
p
1
t
8e
p
w
_EOF
echo
echo -e "\033[40;32m完成！\033[40;37m"
echo -e "\033[1;40;31m[-] 已经创建分区：${1}1\033[0m"
}
function part_rm() {
echo -e "\033[1;40;31m[+] 使用fdisk删除分区\033[0m"
echo -e "\033[40;32m开始操作：\033[40;37m"
count=$(fdisk -l /dev/sdb |grep dev |grep -v Disk |wc -l)
if [ $count -lt 2 ]; then
fdisk $1 <<_EOF
d
p
w
_EOF
echo
echo -e "\033[40;32m完成！\033[40;37m"
echo -e "\033[1;40;31m[-] 已经删除分区：${1}1\033[0m"
echo
else
echo -e "\033[1;40;31m[-] 这个磁盘有多个分区，请先检查确认！\033[0m"
fi
}
function usage() {
cat <<_EOF
usage: $0 type device
$0 lvm /dev/sdb
$0 rm /dev/sdb
_EOF
}
case $1 in
lvm|rm)
part_$1 $2
;;
*)
usage
;;
esac原文地址：http://nosmoking.blog.51cto.com/3263888/1640926
