1 LVM的一些术语
PV（Physical Volume):物理卷
PE（Physical Extent):物理存储块，存储单元
LV（Logic Volume):逻辑卷
LE（Logic Volume):逻辑存储块，存储单元
VG（Volume Group):卷组，PV组
LVM通过把多个物理存储规划到一个大硬盘也就是VG中通过自带的一些进行文件系统级别的管理
大致步骤如下：
fdisk ---> create PV ---> create VG or add to VG --->create LV ---> format LV and mount the partion
2 实验环境
vm12下的debian 8
3 创建lvm
3.1 通过fdisk创建一个LVM格式的分区
root@liuliancao:~# fdisk /dev/sdb
Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p): p #为主分区，或者选择新建扩展分区再新建一个逻辑分区
Partition number (1-4, default 1):
First sector (2048-41943039, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-41943039, default 41943039): +10G
Created a new partition 1 of type 'Linux' and of size 10 GiB.
Command (m for help): t #修改分区类型
Selected partition 1
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'.
Command (m for help): p
Disk /dev/sdb: 20 GiB, 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
Disklabel type: dos
Disk identifier: 0x4056b7d4
Device Boot Start End Sectors Size Id Type
/dev/sdb1 2048 20973567 20971520 10G 8e Linux LVM
Command (m for help): w #写入保存
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.
3.2 创建PV
一般只需要一个参数
root@liuliancao:~# pvcreate /dev/sdb1
Physical volume "/dev/sdb1" successfully created
root@liuliancao:~# pvdisplay /dev/sdb1
"/dev/sdb1" is a new physical volume of "10.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sdb1
VG Name
PV Size 10.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID bujqYf-GO73-DebW-flTi-Xnmj-jug1-MaIlCw
3.3 创建VG并加入把lvm卷加入VG,-s可以指定PE大小，默认4M
root@liuliancao:~# vgcreate liulianca_test /dev/sdb1
Volume group "liulianca_test" successfully created
root@liuliancao:~# vgdisplay
--- Volume group ---
VG Name liulianca_test
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 10.00 GiB
PE Size 4.00 MiB
Total PE 2559
Alloc PE / Size 0 / 0
Free PE / Size 2559 / 10.00 GiB
VG UUID HQsd1f-XU0o-4rUZ-q60o-KrT2-wMTb-SrTT7n
3.4 创建LV -L指定大小，-n指定name，最后接上VG的名称
root@liuliancao:~# lvcreate -L 1G -n lqx liulianca_test
Logical volume "lqx" created
root@liuliancao:~# lvdisplay
--- Logical volume ---
LV Path /dev/liulianca_test/lqx
LV Name lqx
VG Name liulianca_test
LV UUID GeZhTn-Tjb5-Fl7L-wZKu-wvcg-agbj-zaddza
LV Write Access read/write
LV Creation host, time liuliancao, 2015-10-26 01:16:37 -0700
LV Status available
# open 0
LV Size 1.00 GiB
Current LE 256
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 254:5
3.5 格式化和挂载，这个就比较容易了
root@liuliancao:~# mke2fs -t ext3 /dev/liulianca_test/lqx
mke2fs 1.42.12 (29-Aug-2014)
Creating filesystem with 262144 4k blocks and 65536 inodes
Filesystem UUID: 0db59220-379a-4c14-84da-c2f4b0b9f085
Superblock backups stored on blocks:
32768, 98304, 163840, 229376
Allocating group tables: done
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
root@liuliancao:~# mkdir /lvm_test
root@liuliancao:~# mount /dev/liulianca_test/lqx /lvm_test
root@liuliancao:~# ls /lvm_test
lost+found
root@liuliancao:~# echo "/dev/liulianca_test/lqx/lvm_test /lvm_test ext3 defaults 0 0" >> /etc/fstab
简单的LVM使用就是这样了，下面再说下可能甬道的LVM管理
