运维必备基础之LVM逻辑卷管理

整合小容量磁盘和实现分区的动态伸缩。
boot用来存放引导文件，不要基于LVM创建,开机的过程中不识别逻辑卷。
PV（Physical Volume，物理卷）：物理分区，或整个物理磁盘，由PE（Physical Extent，基本单元）组成。
VG（Volume Group，卷组）：一个或多个物理卷组成的整体。
LV（Logical Volume，逻辑卷）：从卷组中分割出的一块逻辑存储空间，课通过格式化建立文件系统。

功能	物理卷	卷组	逻辑卷
scan（扫描）	pvscan	vgscan	lvscan
create（创建）	pvcreate	vgcreate	lvcreate
display（显示）	pvdisplay	vgdisplay	lvdisplay
remove（删除）	pvremove	vgremove	lvremove
extend（扩展）		vgextend	lvextend
reduce（减少）		vgreduce	lvreduce

图形管理程序：system-config-lvm
LVM创建过程：创建PV-->创建-->VG-->创建LV-->格式化LV-->挂载
LVM删除过程：卸载-->删除LV-->删除VG-->删除PV
pvcreate 设备路径
vgcreate 卷组名 设备路径
lvcreate -L 大小 -n 逻辑卷名 卷组名
创建LVM实验步骤：
添加一块硬盘20GB：
[root@node0 ~]# lsblk # 查看添加的硬盘
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sr0 11:0 1 3.6G 0 rom /dvd
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 200M 0 part /boot
├─sda2 8:2 0 1000M 0 part [SWAP]
└─sda3 8:3 0 18.8G 0 part /
sdb 8:16 0 20G 0 disk
[root@node0 ~]# parted /dev/sdb # 对硬盘进行分区
GNU Parted 2.1
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mklabel # 创建分区表
New disk label type? gpt # 分区表类型为GPT
(parted) mkpart # 创建分区
Partition name? []?
File system type? [ext2]? ext4 # 写入文件系统的类型
Start? 0 # 开始位置
End? 50% # 结束位置
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? i # 忽略
(parted) p # 显示分区结果
Model: ATA VMware Virtual S (scsi)
Disk /dev/sdb: 21.5GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number Start End Size File system Name Flags
1 17.4kB 10.7GB 10.7GB

(parted) mkpart
Partition name? []?
File system type? [ext2]? ext4
Start? 50%
End? 100%
(parted) p
Model: ATA VMware Virtual S (scsi)
Disk /dev/sdb: 21.5GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number Start End Size File system Name Flags
1 17.4kB 10.7GB 10.7GB
2 10.7GB 21.5GB 10.7GB

(parted) quit
[root@node0 ~]# pvscan # 扫描现有的PV
No matching physical volumes found
[root@node0 ~]# pvcreate /dev/sdb1 /dev/sdb2 # 创建PV
Physical volume "/dev/sdb1" successfully created
Physical volume "/dev/sdb2" successfully created
[root@node0 ~]# vgcreate vg01 /dev/sdb1 /dev/sdb2
Volume group "vg01" successfully created
[root@node0 ~]# vgscan # 扫描现有的VG
Reading all physical volumes. This may take a while...
Found volume group "vg01" using metadata type lvm2
[root@node0 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
vg01 2 0 0 wz--n- 19.99g 19.99g
[root@node0 ~]# lvcreate -L 15GB -n lv01 vg01 # 创建LV
Logical volume "lv01" created.
[root@node0 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv01 vg01 -wi-a----- 15.00g
[root@node0 ~]# lvscan # 扫描现有的LV
ACTIVE '/dev/vg01/lv01' [15.00 GiB] inherit
[root@node0 ~]# mkfs.ext4 /dev/vg01/lv01 # 格式化LV
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
983040 inodes, 3932160 blocks
196608 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4026531840
120 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 39 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@node0 ~]# lsblk # 查看设备
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sr0 11:0 1 3.6G 0 rom /dvd
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 200M 0 part /boot
├─sda2 8:2 0 1000M 0 part [SWAP]
└─sda3 8:3 0 18.8G 0 part /
sdb 8:16 0 20G 0 disk
├─sdb1 8:17 0 10G 0 part
│ └─vg01-lv01 (dm-0) 253:0 0 15G 0 lvm
└─sdb2 8:18 0 10G 0 part
└─vg01-lv01 (dm-0) 253:0 0 15G 0 lvm
扩展、缩减LV：
[root@node0 ~]# lvextend -L +2GB /dev/vg01/lv01 # 扩展LV
Size of logical volume vg01/lv01 changed from 15.00 GiB (3840 extents) to 17.00 GiB (4352 extents).
Logical volume lv01 successfully resized
[root@node0 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv01 vg01 -wi-a----- 17.00g
[root@node0 ~]# lvreduce -L -1GB /dev/vg01/lv01 # 减小LV
WARNING: Reducing active logical volume to 16.00 GiB
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce lv01? [y/n]: y
Size of logical volume vg01/lv01 changed from 17.00 GiB (4352 extents) to 16.00 GiB (4096 extents).
Logical volume lv01 successfully resized
扩展、缩减VG：
[root@node0 ~]# lsblk # 添加硬盘
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sr0 11:0 1 3.6G 0 rom /dvd
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 200M 0 part /boot
├─sda2 8:2 0 1000M 0 part [SWAP]
└─sda3 8:3 0 18.8G 0 part /
sdb 8:16 0 20G 0 disk
├─sdb1 8:17 0 10G 0 part
│ └─vg01-lv01 (dm-0) 253:0 0 16G 0 lvm
└─sdb2 8:18 0 10G 0 part
└─vg01-lv01 (dm-0) 253:0 0 16G 0 lvm
sdc 8:32 0 20G 0 disk
[root@node0 ~]# parted /dev/sdc # 为新添加的硬盘分区
GNU Parted 2.1
Using /dev/sdc
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) mkl
New disk label type? Gpt # 创建分区表
(parted) mkpart # 创建分区
Partition name? []?
File system type? [ext2]? ext4
Start? 0%
End? 100%
(parted) p # 查看结果
Model: ATA VMware Virtual S (scsi)
Disk /dev/sdc: 21.5GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number Start End Size File system Name Flags
1 1049kB 21.5GB 21.5GB

(parted) quit # 退出parted分区工具
Information: You may need to update /etc/fstab.
[root@node0 ~]# lsblk # 查看结果
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sr0 11:0 1 3.6G 0 rom /dvd
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 200M 0 part /boot
├─sda2 8:2 0 1000M 0 part [SWAP]
└─sda3 8:3 0 18.8G 0 part /
sdb 8:16 0 20G 0 disk
├─sdb1 8:17 0 10G 0 part
│ └─vg01-lv01 (dm-0) 253:0 0 16G 0 lvm
└─sdb2 8:18 0 10G 0 part
└─vg01-lv01 (dm-0) 253:0 0 16G 0 lvm
sdc 8:32 0 20G 0 disk
└─sdc1 8:33 0 20G 0 part
[root@node0 ~]# pvcreate /dev/sdc1 # 创建PV
Physical volume "/dev/sdc1" successfully created
[root@node0 ~]# vgextend vg01 /dev/sdc1 # 扩展VG
Volume group "vg01" successfully extended
[root@node0 ~]# vgs # 查看扩展结果
VG #PV #LV #SN Attr VSize VFree
vg01 3 1 0 wz--n- 39.99g 23.99g
root@node0 ~]# lvextend -L +10GB -n /dev/vg01/lv01 # 扩展LV
Size of logical volume vg01/lv01 changed from 16.00 GiB (4096 extents) to 26.00 GiB (6656 extents).
Logical volume lv01 successfully resized
[root@node0 ~]# lvs # 查看扩展结果
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
lv01 vg01 -wi-a----- 26.00g
挂载LV：
[root@node0 ~]# mkdir /lv01_data # 创建用于挂载的目录
[root@node0 ~]# ll /dev/vg01/lv01
lrwxrwxrwx. 1 root root 7 Nov 20 16:59 /dev/vg01/lv01 -> ../dm-0
[root@node0 ~]# vim /etc/fstab # 编辑/etc/fstab配置文件
/dev/vg01/lv01 /lv01_data ext4 defaults 0 0
[root@node0 ~]# mount -a # 刷新/etc/fstab
[root@node0 ~]# lsblk # 查看结果
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sr0 11:0 1 3.6G 0 rom /dvd
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 200M 0 part /boot
├─sda2 8:2 0 1000M 0 part [SWAP]
└─sda3 8:3 0 18.8G 0 part /
sdb 8:16 0 20G 0 disk
├─sdb1 8:17 0 10G 0 part
│ └─vg01-lv01 (dm-0) 253:0 0 26G 0 lvm /lv01_data
└─sdb2 8:18 0 10G 0 part
└─vg01-lv01 (dm-0) 253:0 0 26G 0 lvm /lv01_data
sdc 8:32 0 20G 0 disk
└─sdc1 8:33 0 20G 0 part
└─vg01-lv01 (dm-0) 253:0 0 26G 0 lvm /lv01_data
缩减文件系统：
[root@node0 ~]# resize2fs /dev/vg01/lv01 10G
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/vg01/lv01 to 2621440 (4k) blocks.
The filesystem on /dev/vg01/lv01 is now 2621440 blocks long.
删除LVM：
[root@node0 ~]# umount /lv01_data/ # 卸载文件系统
[root@node0 ~]# lvremove /dev/vg01/lv01 # 删除LV
Do you really want to remove active logical volume lv01? [y/n]: y # 确认删除
Logical volume "lv01" successfully removed
[root@node0 ~]# lvs # 查看结果
[root@node0 ~]# vgremove /dev/vg01 # 删除VG
Volume group "vg01" successfully removed
[root@node0 ~]# vgs # 查看结果
[root@node0 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sr0 11:0 1 3.6G 0 rom /dvd
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 200M 0 part /boot
├─sda2 8:2 0 1000M 0 part [SWAP]
└─sda3 8:3 0 18.8G 0 part /
sdb 8:16 0 20G 0 disk
├─sdb1 8:17 0 10G 0 part
└─sdb2 8:18 0 10G 0 part
sdc 8:32 0 20G 0 disk
└─sdc1 8:33 0 20G 0 part
[root@node0 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sdb1 lvm2 --- 10.00g 10.00g
/dev/sdb2 lvm2 --- 10.00g 10.00g
/dev/sdc1 lvm2 --- 20.00g 20.00g
[root@node0 ~]# pvremove /dev/sdb1 /dev/sdb2 /dev/sdc1 # 删除PV
Labels on physical volume "/dev/sdb1" successfully wiped
Labels on physical volume "/dev/sdb2" successfully wiped
Labels on physical volume "/dev/sdc1" successfully wiped
[root@node0 ~]# pvs # 查看结果
删除/etc/fstab文件中的配置条目。