LVM 磁盘工具
LVM是Linux系统中用于管理磁盘分区的命令行工具。该工具通过纯软件方式将多个块设备组织为逻辑卷，支持在线调整逻辑卷空间并集成快照功能以实现数据备份。
说明：此操作在centos7下进行，如果是centos6发行版，需要注意格式化LV的文件系统类型（centos7.0开始默认文件系统是xfs，centos6是ext4）、最后一步写入系统的类型
ubuntu也可以使用此文档
安装LVM
# centos
yum install -y lvm2
# ubuntu
apt install -y lvm2命令大全
这里就是常用的创建分区所有使用的命令了，注意部分命令例如lsblk 只会提及一次，如想查看完整操作请看下一小节。
# 查看磁盘分区情况（虚拟磁盘通常是vdx、sata磁盘是sdx、nvme是nvmex）这里使用vdb作为演示
lsblk
# 使用parted工具操作磁盘（格式化磁盘）
parted /dev/vdb
# 查看磁盘信息
print
# 修改为gpt分区表
mklabel gpt
# 创建主分区(如果创建一个分区，最后一个为最大容量)
mkpart primary 0 1045GB
# 如果有错误就忽略，如果有覆盖选项就Y覆盖
# 创建完成后可以再次运行print查看磁盘信息
# 标记1分区为lvm
set 1 lvm on
# 退出分区工具
quit
# 重读分区表 可以再次运行lsblk进行查看分区
partprobe /dev/vdb
# ---------------------------创建分区操作---------------------------
# PV操作
## 创建pv (vdb1就是lsblk的vdb下面的一个分区)
pvcreate -v /dev/vdb1
## 查看pv 这里主要查看创建的pv有没有成功创建，注意这里可能会包含系统的pv
pvdisplay
# VG操作
## 创建vg 这里的vg01就是创建的vg名称
vgcreate -s 4M vg01 /dev/vdb1
## 查看vg 这里同样会包含系统的vg
vgdisplay
# LV操作
## 创建lv 这里的vg01就是vg名称 lv01就是创建的lv名称
lvcreate -l 100%FREE -n lv01 vg01
## 查看lv 这里同样会包含系统的vg
lvdisplay
# 格式化分区 主要演示格式化为ext4
## 主要语法为 mkfs.ext4 /dev/<vg名称>/<lv名称>
mkfs.ext4 /dev/vg01/lv01
# 进行挂载操作
mkdir /app
mount /dev/vg01/lv01 /app
# 永久写入挂载点
## 查看系统当前挂载信息
blkid
## 写入fstab文件
echo "UUID=<UUID> /app ext4 defaults 0 0" >> /etc/fstab
# ---------------------------扩容分区操作---------------------------
# VG操作
## 扩展vg，将pv全部扩展到vg下
##vgextend <VG Name> <PV Name>
vgextend vg01 /dev/vdb1
# 查看LV
lvdisplay
# LV操作
## 扩展lv，将vg全部扩展到lv下
lvextend -l +100%FREE <LV Path>
## 缩小lv分区
lvreduce -L 100G <LV Path>
# 加载到系统
## 参数为 LV path，**被扩容的挂载点一定是LVM格式
xfs_growfs <LV Path>
# ---------------------------删除分区操作---------------------------
# 删除挂载点
## 如果fstab内有配置需要同步删除
umount -v /dev/vg01/lv01
## 删除目录（可选）
rm -rf /app
# LV操作
## 删除LV
lvremove /dev/vg01/lv01
## 查看LV
lvdisplay
# VG操作
## 删除vg
vgremove vg01
## 查看vg
vgdisplay真机实践
1、查看当前磁盘
[root@fsddxtclgj9vm900419 ~]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/centos-root xfs 44G 3.7G 41G 9% /
devtmpfs devtmpfs 7.8G 0 7.8G 0% /dev
tmpfs tmpfs 7.8G 0 7.8G 0% /dev/shm
tmpfs tmpfs 7.8G 777M 7.0G 10% /run
tmpfs tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup
/dev/vda1 xfs 1014M 179M 836M 18% /boot
tmpfs tmpfs 1.6G 36K 1.6G 1% /run/user/0
tmpfs tmpfs 1.6G 40K 1.6G 1% /run/user/10012、查看块分区
[root@fsddxtclgj9vm900419 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
vda 252:0 0 50G 0 disk
├─vda1 252:1 0 1G 0 part /boot
└─vda2 252:2 0 49G 0 part
├─centos-root 253:0 0 44G 0 lvm /
└─centos-swap 253:1 0 5G 0 lvm [SWAP]
vdb 252:16 0 974G 0 disk可以看到 /dev/vdb 为新增的磁盘
3、格式化磁盘
[root@fsddxtclgj9vm900419 ~]# parted /dev/vdb
GNU Parted 3.1
Using /dev/vdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Error: /dev/vdb: unrecognised disk label
Model: Virtio Block Device (virtblk)
Disk /dev/vdb: 1046GB
Sector size (logical/physical): 512B/512B
Partition Table: unknown
Disk Flags:
(parted) mklabel gpt
(parted) mkpart primary 0 1045GB
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? i
(parted) print
Model: Virtio Block Device (virtblk)
Disk /dev/vdb: 1046GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 1045GB 1045GB primary
(parted) set 1 lvm on
(parted) print
Model: Virtio Block Device (virtblk)
Disk /dev/vdb: 1046GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 1045GB 1045GB primary lvm
(parted) quit
Information: You may need to update /etc/fstab以上 (parted) 开头的代表输入的命令，具体功能可以通过 help 查看
4、重读分区表
partprobe /dev/vdb5、重新查看块分区
[root@fsddxtclgj9vm900419 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
vda 252:0 0 50G 0 disk
├─vda1 252:1 0 1G 0 part /boot
└─vda2 252:2 0 49G 0 part
├─centos-root 253:0 0 44G 0 lvm /
└─centos-swap 253:1 0 5G 0 lvm [SWAP]
vdb 252:16 0 974G 0 disk
└─vdb1 252:17 0 973.2G 0 part可以看到vdb下多了vdb1，这个用来创建pv
6、创建PV
[root@fsddxtclgj9vm900419 ~]# pvcreate -v /dev/vdb1
Wiping internal VG cache
Wiping cache of LVM-capable devices
Wiping signatures on new PV /dev/vdb1.
Set up physical volume for "/dev/vdb1" with 2041015592 available sectors.
Zeroing start of device /dev/vdb1.
Writing physical volume data to disk "/dev/vdb1".
Physical volume "/dev/vdb1" successfully created.注意
PV创建好之后，到这一步可以选择扩展或者新建挂载点，扩容的前提条件是扩容挂载点的磁盘格式是LVM格式，这里先演示新建挂载点然后删除挂载点并扩容
7、新增LVM挂载
查看PV
[root@fsddxtclgj9vm900419 ~]# pvdisplay
--- Physical volume ---
PV Name /dev/vda2
VG Name centos
PV Size <49.00 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 12543
Free PE 0
Allocated PE 12543
PV UUID CCUeq0-ZnG9-iUY8-dPOj-fVOa-XC10-ooGyle
"/dev/vdb1" is a new physical volume of "973.23 GiB"
--- NEW Physical volume ---
PV Name /dev/vdb1
VG Name
PV Size 973.23 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID vUoC7C-MIP2-iwXr-0SWu-c2Wz-yb6o-qFrfo1注意看 VG Name，前面的是系统安装时选择LVM格式的，后面的还没有创建，所以 VG Name 为空
新建VG
[root@fsddxtclgj9vm900419 ~]# vgcreate -s 4M vg01 /dev/vdb1
Volume group "vg01" successfully created查看VG
[root@fsddxtclgj9vm900419 ~]# vgdisplay
--- Volume group ---
VG Name vg01
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 973.23 GiB
PE Size 4.00 MiB
Total PE 249147
Alloc PE / Size 0 / 0
Free PE / Size 249147 / 973.23 GiB
VG UUID hb8zoy-kKjU-VXD5-EjCN-8hS2-MOzf-lq3O5j
--- Volume group ---
VG Name centos
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 2
Open LV 2
Max PV 0
Cur PV 1
Act PV 1
VG Size <49.00 GiB
PE Size 4.00 MiB
Total PE 12543
Alloc PE / Size 12543 / <49.00 GiB
Free PE / Size 0 / 0
VG UUID kSwsMj-4FKB-zwFq-7MBq-EfOD-rccg-HC59x9可以看到 vg01 为新建的VG
新建LV
[root@fsddxtclgj9vm900419 ~]# lvcreate -l 100%FREE -n lv01 vg01
Logical volume "lv01" created格式化LV
格式化文件系统类型有xfs，ext4，这里测试使用ext4格式，默认centos7下使用xfs格式，centos6为ext4格式
[root@fsddxtclgj9vm900419 ~]# mkfs.ext4 /dev/vg01/lv01
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
63782912 inodes, 255126528 blocks
12756326 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2403336192
7786 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,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done新建挂载点并挂载
mkdir /app
mount /dev/vg01/lv01 /app查看新增挂载后的块分区
[root@fsddxtclgj9vm900419 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
vda 252:0 0 50G 0 disk
├─vda1 252:1 0 1G 0 part /boot
└─vda2 252:2 0 49G 0 part
├─centos-root 253:0 0 44G 0 lvm /
└─centos-swap 253:1 0 5G 0 lvm [SWAP]
vdb 252:16 0 974G 0 disk
└─vdb1 252:17 0 973.2G 0 part
└─vg01-lv01 253:2 0 973.2G 0 lvm /app可以看到新增磁盘以LVM格式挂载在 /app 下
永久写入挂载点
blkid
#/dev/mapper/vg01-lv01 on /opt type ext4 (rw,relatime)
# echo "UUID=<UUID> /app ext4 defaults 0 0" >> /etc/fstab[root@docker-server ~]# blkid
/dev/sda1: SEC_TYPE="msdos" UUID="F312-EB5D" TYPE="vfat" PARTLABEL="EFI System Partition" PARTUUID="7526c319-8c70-4fa9-ad1a-7a9a906c0f7c"
/dev/sda2: UUID="a169778d-bcee-41d3-899e-aa68e670eb54" TYPE="xfs" PARTUUID="b9de11c9-a9a8-46c7-8484-a3f0450f648f"
/dev/sda3: UUID="4WIoYK-aQng-dGMv-YYjq-RXaj-XKMV-o0RYCL" TYPE="LVM2_member" PARTUUID="b0ebc437-996e-4a3c-b6d3-cf5692413688"
/dev/sdb1: UUID="PHHm7S-6haw-EeGN-2xRl-Cxna-3C9N-4QlPIy" TYPE="LVM2_member" PARTLABEL="primary" PARTUUID="68320f1b-25b0-4070-8a22-79af2af7aa69"
/dev/mapper/centos-root: UUID="375718d4-698b-4709-b721-2c652a87c118" TYPE="xfs"
/dev/mapper/centos-swap: UUID="d7e852bb-0ef8-4545-a3cb-4fb12b8fb9ff" TYPE="swap"
# lvm
/dev/mapper/vg01-lv01: UUID="37bbfff9-76da-4515-a9e5-b8820ea523e5" TYPE="ext4"
/dev/mapper/centos-home: UUID="d3f5743c-588a-4bc1-bb6a-51775db4713e" TYPE="xfs"
[root@docker-server ~]# cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Wed Jul 3 21:16:34 2024
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root / xfs defaults 0 0
UUID=a169778d-bcee-41d3-899e-aa68e670eb54 /boot xfs defaults 0 0
UUID=F312-EB5D /boot/efi vfat umask=0077,shortname=winnt 0 0
/dev/mapper/centos-home /home xfs defaults 0 0
/dev/mapper/centos-swap swap swap defaults 0 0
# 写入
UUID=37bbfff9-76da-4515-a9e5-b8820ea523e5 /app ext4 defaults 0 08、删除LVM挂载点
删除挂载点
[root@fsddxtclgj9vm900419 ~]# umount -v /dev/vg01/lv01
umount: /app (/dev/mapper/vg01-lv01) unmounted查看块设备
[root@fsddxtclgj9vm900419 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
vda 252:0 0 50G 0 disk
├─vda1 252:1 0 1G 0 part /boot
└─vda2 252:2 0 49G 0 part
├─centos-root 253:0 0 44G 0 lvm /
└─centos-swap 253:1 0 5G 0 lvm [SWAP]
vdb 252:16 0 974G 0 disk
└─vdb1 252:17 0 973.2G 0 part
└─vg01-lv01 253:2 0 973.2G 0 lvm可以看到 /app 挂载点删除了，删除 /app 目录
rm -rf /app删除LV
参数为 LV Path
[root@fsddxtclgj9vm900419 ~]# lvremove /dev/vg01/lv01
Do you really want to remove active logical volume vg01/lv01? [y/n]: y
Logical volume "lv01" successfully removed删除VG
参数为 VG Name
[root@fsddxtclgj9vm900419 ~]# vgremove vg01
Volume group "vg01" successfully removed扩容VG
参数为 VG Name 和 PV Name
[root@fsddxtclgj9vm900419 ~]# vgextend centos /dev/vdb1
Volume group "centos" successfully extended此时 PV /dev/vdb1 全部扩展到 VG centos下
查看LV
[root@fsddxtclgj9vm900419 ~]# lvdisplay
--- Logical volume ---
LV Path /dev/centos/swap
LV Name swap
VG Name centos
LV UUID PCx0yU-o9JZ-R92O-lI01-f8EU-DKyM-etst0H
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2018-12-24 16:46:31 +0800
LV Status available
# open 2
LV Size 5.00 GiB
Current LE 1280
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:1
--- Logical volume ---
LV Path /dev/centos/root
LV Name root
VG Name centos
LV UUID Idf9IO-AxkA-tS1C-FTgN-FsLT-d3Zk-7o1W5E
LV Write Access read/write
LV Creation host, time localhost.localdomain, 2018-12-24 16:46:31 +0800
LV Status available
# open 1
LV Size <44.00 GiB
Current LE 11263
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:0通过查看，系统安装时选择的磁盘格式是LVM并且有两个分区，接下来扩展根分区
扩展LV分区
参数为 LV Path
[root@fsddxtclgj9vm900419 ~]# lvextend -l +100%FREE /dev/centos/root
Size of logical volume centos/root changed from <44.00 GiB (11263 extents) to <1017.23 GiB (260410 extents).
Logical volume centos/root successfully resized如果发现误操作，需要还原，可以通过以下命令缩小LV分区
lvreduce -L 1017.2G /dev/centos/root加载扩容到系统
此时查看系统可以看到已经扩容，但没有加载到文件系统
[root@fsddxtclgj9vm900419 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
vda 252:0 0 50G 0 disk
├─vda1 252:1 0 1G 0 part /boot
└─vda2 252:2 0 49G 0 part
├─centos-root 253:0 0 1017.2G 0 lvm /
└─centos-swap 253:1 0 5G 0 lvm [SWAP]
vdb 252:16 0 974G 0 disk
└─vdb1 252:17 0 973.2G 0 part
└─centos-root 253:0 0 1017.2G 0 lvm /
[root@fsddxtclgj9vm900419 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 44G 3.7G 41G 9% /
devtmpfs 7.8G 0 7.8G 0% /dev
tmpfs 7.8G 0 7.8G 0% /dev/shm
tmpfs 7.8G 777M 7.0G 10% /run
tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup
/dev/vda1 1014M 179M 836M 18% /boot
tmpfs 1.6G 36K 1.6G 1% /run/user/0
tmpfs 1.6G 40K 1.6G 1% /run/user/1001加载扩容到系统 参数为 LV path，被扩容的挂载点一定是LVM格式
[root@fsddxtclgj9vm900419 ~]# xfs_growfs /dev/centos/root
meta-data=/dev/mapper/centos-root isize=512 agcount=4, agsize=2883328 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=11533312, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=5631, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 11533312 to 266659840说明：若使用ext4文件格式（centos6），是使用resize2fs命令来生效 查看磁盘
[root@fsddxtclgj9vm900419 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/centos-root 1018G 3.7G 1014G 1% /
devtmpfs 7.8G 0 7.8G 0% /dev
tmpfs 7.8G 0 7.8G 0% /dev/shm
tmpfs 7.8G 777M 7.0G 10% /run
tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup
/dev/vda1 1014M 179M 836M 18% /boot
tmpfs 1.6G 36K 1.6G 1% /run/user/0
tmpfs 1.6G 40K 1.6G 1% /run/user/1001