LVM逻辑卷管理器简介和参考实例

一、LVM简介

LVM（Logical Volume Manager，逻辑卷管理器）是Linux系统用于对硬盘分区进行管理的一种机制，其创建初衷是为了解决硬盘设备在创建分区后不易修改分区大小的缺陷。尽管对传统的硬盘分区进行强制扩容或缩容从理论上来讲是可行的，但是却可能造成数据的丢失。而LVM技术是在硬盘分区和文件系统之间添加了一个逻辑层，它提供了一个抽象的卷组，可以把多块硬盘进行卷组合并。这样一来，用户不必关心物理硬盘设备的底层架构和布局，就可以实现对硬盘分区的动态调整

二、实验环境

操作平台：VMware Workstation 17 Pro

虚机操作系统：RokcyLinux 8.9

三、参考实例

3.1 创建物理卷（PV）

LVM支持使用整块磁盘创建PV，或用分区创建PV

例如使用/dev/sdb磁盘创建PV

[root@localhost ~]# parted /dev/sdb print  # 查看磁盘信息
Error: /dev/sdb: unrecognised disk label
Model: VMware, VMware Virtual S (scsi)                                    
Disk /dev/sdb: 10.7GB
Sector size (logical/physical): 512B/512B
Partition Table: unknown
Disk Flags: 
[root@localhost ~]# pvcreate /dev/sdb  # 创建
  Physical volume "/dev/sdb" successfully created.

以下三条命令均可查看pv状态

[root@localhost ~]# pvscan 
  PV /dev/sda2   VG rl              lvm2 [<49.00 GiB / 0    free]
  PV /dev/sdb                       lvm2 [10.00 GiB]
  Total: 2 [<59.00 GiB] / in use: 1 [<49.00 GiB] / in no VG: 1 [10.00 GiB]
[root@localhost ~]# pvs
  PV         VG Fmt  Attr PSize   PFree 
  /dev/sda2  rl lvm2 a--  <49.00g     0 
  /dev/sdb      lvm2 ---   10.00g 10.00g
[root@localhost ~]# pvdisplay /dev/sdb
  "/dev/sdb" is a new physical volume of "10.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdb
  VG Name               
  PV Size               10.00 GiB
  Allocatable           NO
  PE Size               0   
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               J24xM9-b5SN-NlA0-q8cv-jQw3-eBRW-aLdNKk

使用磁盘分区创建PV

[root@localhost ~]# fdisk /dev/sdc  # 首先对磁盘进行分区


Welcome to fdisk (util-linux 2.32.1).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.


Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0xa6c9a99a.


Command (m for help): n  # 创建新分区
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): p  # 创建主分区
Partition number (1-4, default 1):   # 分区编号，默认为第一个分区
First sector (2048-20971519, default 2048): # 分区的起始扇区，默认即可，直接回车
Last sector, +sectors or +size{K,M,G,T,P} (2048-20971519, default 20971519): +5G  # 分区大小5G


Created a new partition 1 of type 'Linux' and of size 5 GiB.


Command (m for help): t  # 更改分区类型
Selected partition 1
Hex code (type L to list all codes): 8e  # 选择逻辑卷类型，对应编号为8e
Changed type of partition 'Linux' to 'Linux LVM'.


Command (m for help): p  # 打印分区信息
Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 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: 0xa6c9a99a


Device     Boot Start      End  Sectors Size Id Type
/dev/sdc1        2048 10487807 10485760   5G 8e Linux LVM


Command (m for help): w  # 保存分区表
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

[root@localhost ~]# pvcreate /dev/sdc1  # 创建
  Physical volume "/dev/sdc1" successfully created.
[root@localhost ~]# pvs
  PV         VG Fmt  Attr PSize   PFree 
  /dev/sda2  rl lvm2 a--  <49.00g     0 
  /dev/sdb      lvm2 ---   10.00g 10.00g
  /dev/sdc1     lvm2 ---    5.00g  5.00g
[root@localhost ~]# pvdisplay /dev/sdc1
  "/dev/sdc1" is a new physical volume of "5.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdc1
  VG Name               
  PV Size               5.00 GiB
  Allocatable           NO
  PE Size               0   
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               K3MapS-m1yx-1E5p-pSjw-OTLB-OdMI-hPNCMe

3.2 创建卷组（VG）

例如：使用物理卷“/dev/sdb”创建一个名为“vgtest”的卷组

[root@localhost ~]# vgcreate vgtest /dev/sdb
  Volume group "vgtest" successfully created

以下命令均可查看VG的状态

[root@localhost ~]# vgscan
  Found volume group "vgtest" using metadata type lvm2
  Found volume group "rl" using metadata type lvm2
[root@localhost ~]# vgs
  VG     #PV #LV #SN Attr   VSize   VFree  
  rl       1   2   0 wz--n- <49.00g      0 
  vgtest   1   0   0 wz--n- <10.00g <10.00g
  [root@localhost ~]# vgdisplay vgtest
  --- Volume group ---
  VG Name               vgtest
  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  # 默认的PE大小为4MiB
  Total PE              2559
  Alloc PE / Size       0 / 0   
  Free  PE / Size       2559 / <10.00 GiB
  VG UUID               yb2LkE-6N02-Pv6w-6Wb6-sVII-1E1c-9VrNrj

也可以在创建卷组时指定PE的大小，使用“-s”参数指定，单位是“M”

[root@localhost ~]# vgcreate -s 2M vgtest1 /dev/sdc1
  Volume group "vgtest1" successfully created
[root@localhost ~]# pvdisplay /dev/sdc1
  --- Physical volume ---
  PV Name               /dev/sdc1
  VG Name               vgtest1
  PV Size               5.00 GiB / not usable 2.00 MiB
  Allocatable           yes 
  PE Size               2.00 MiB  # PE大小为2
  Total PE              2559
  Free PE               2559
  Allocated PE          0
  PV UUID               K3MapS-m1yx-1E5p-pSjw-OTLB-OdMI-hPNCMe

可以使用多个PV来创建卷组，这样创建出来的VG容量就是多个PV的总和

[root@localhost ~]# pvcreate /dev/sdd
  Physical volume "/dev/sdd" successfully created.
[root@localhost ~]# pvcreate /dev/sde
  Physical volume "/dev/sde" successfully created.
[root@localhost ~]# 
[root@localhost ~]# vgcreate vgtest2 /dev/sdd /dev/sde
  Volume group "vgtest2" successfully created
[root@localhost ~]# vgdisplay vgtest2
  --- Volume group ---
  VG Name               vgtest2
  System ID             
  Format                lvm2
  Metadata Areas        2
  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                2
  Act PV                2
  VG Size               19.99 GiB
  PE Size               4.00 MiB
  Total PE              5118
  Alloc PE / Size       0 / 0   
  Free  PE / Size       5118 / 19.99 GiB
  VG UUID               jI8V7c-A4Pa-W2GU-cGc4-kglH-IYii-TNfFRp

3.3 创建逻辑卷（LV）

使用卷组“vgtest”来创建逻辑卷，名为“lvtest”，将“vgtest”的所有空间分配给“lvtest”

[root@localhost ~]# lvcreate -l 100%FREE vgtest -n lvtest
  Logical volume "lvtest" created.

以下命令均可查看逻辑卷状态

[root@localhost ~]# lvscan
  ACTIVE            '/dev/vgtest/lvtest' [<10.00 GiB] inherit
  ACTIVE            '/dev/rl/swap' [3.91 GiB] inherit
  ACTIVE            '/dev/rl/root' [45.08 GiB] inherit
[root@localhost ~]# lvs
  LV     VG     Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root   rl     -wi-ao----  45.08g                                                    
  swap   rl     -wi-ao----   3.91g                                                    
  lvtest vgtest -wi-a----- <10.00g         
[root@localhost ~]# lvdisplay vgtest/lvtest
  --- Logical volume ---
  LV Path                /dev/vgtest/lvtest
  LV Name                lvtest
  VG Name                vgtest
  LV UUID                hJX97w-kJtH-izv3-5N2U-rlVf-OZfe-8OMedE
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2023-12-30 2257 +0800
  LV Status              available
  # open                 0
  LV Size                <10.00 GiB
  Current LE             2559
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:2

可以在创建逻辑卷时指定其容量

[root@localhost ~]# lvcreate -L 3G vgtest1 -n lvtest1  # 指定LV容量为3G
  Logical volume "lvtest1" created.
[root@localhost ~]# lvdisplay vgtest1/lvtest1
  --- Logical volume ---
  LV Path                /dev/vgtest1/lvtest1
  LV Name                lvtest1
  VG Name                vgtest1
  LV UUID                ltVLNf-oyj0-25Ct-MVmx-VyeC-6y03-9LZdFV
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2023-12-30 2213 +0800
  LV Status              available
  # open                 0
  LV Size                3.00 GiB  # LV容量为3GiB
  Current LE             1536
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:3

也可以在创建逻辑卷时指定为其分配的PE个数，例如，我想为创建的LV分配容量800M的容量，默认PE大小为4M，则为200个PE

[root@localhost ~]# vgdisplay vgtest2
  --- Volume group ---
  VG Name               vgtest2
  System ID             
  Format                lvm2
  Metadata Areas        2
  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                2
  Act PV                2
  VG Size               19.99 GiB
  PE Size               4.00 MiB  # PE大小为4MiB
  Total PE              5118
  Alloc PE / Size       0 / 0   
  Free  PE / Size       5118 / 19.99 GiB
[root@localhost ~]# lvcreate -l 200 vgtest2 -n lvtest2
  Logical volume "lvtest2" created.
[root@localhost ~]# lvdisplay vgtest2/lvtest2
  --- Logical volume ---
  LV Path                /dev/vgtest2/lvtest2
  LV Name                lvtest2
  VG Name                vgtest2
  LV UUID                rdYOR3-ETaO-Lc33-L0Si-ke3a-J3dV-qRTuGs
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2023-12-30 2207 +0800
  LV Status              available
  # open                 0
  LV Size                800.00 MiB  # LV容量为800MiB
  Current LE             200  # 分配到的PE个数为200
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:4

3.4 逻辑卷扩容

例如，如果我想对逻辑卷“lvtest2”进行扩容，增加200M容量

[root@localhost ~]# lvs
  LV      VG      Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  root    rl      -wi-ao----  45.08g                                                    
  swap    rl      -wi-ao----   3.91g                                                    
  lvtest  vgtest  -wi-a----- <10.00g                                                    
  lvtest1 vgtest1 -wi-a-----   3.00g                                                    
  lvtest2 vgtest2 -wi-a----- 800.00m    # 查看到lvtest2使用的是vgtest2这个卷组
[root@localhost ~]# vgs
  VG      #PV #LV #SN Attr   VSize   VFree 
  rl        1   2   0 wz--n- <49.00g     0 
  vgtest    1   1   0 wz--n- <10.00g     0 
  vgtest1   1   1   0 wz--n-  <5.00g <2.00g
  vgtest2   2   1   0 wz--n-  19.99g 19.21g  # 查看到vgtest2还有19.21G的空闲容量
[root@localhost ~]# lvextend -L +200M vgtest2/lvtest2
  Size of logical volume vgtest2/lvtest2 changed from 800.00 MiB (200 extents) to 1000.00 MiB (250 extents).
  Logical volume vgtest2/lvtest2 successfully resized.
[root@localhost ~]# lvdisplay vgtest2/lvtest2
  --- Logical volume ---
  LV Path                /dev/vgtest2/lvtest2
  LV Name                lvtest2
  VG Name                vgtest2
  LV UUID                rdYOR3-ETaO-Lc33-L0Si-ke3a-J3dV-qRTuGs
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2023-12-30 2207 +0800
  LV Status              available
  # open                 0
  LV Size                1000.00 MiB  # 容量增长为1000MiB
  Current LE             250
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:4

也可以指定增加的PE个数来对逻辑卷进行扩容

[root@localhost ~]# lvextend -l +25 vgtest2/lvtest2
  Size of logical volume vgtest2/lvtest2 changed from 1000.00 MiB (250 extents) to 1.07 GiB (275 extents).
  Logical volume vgtest2/lvtest2 successfully resized.
[root@localhost ~]# lvdisplay vgtest2/lvtest2
  --- Logical volume ---
  LV Path                /dev/vgtest2/lvtest2
  LV Name                lvtest2
  VG Name                vgtest2
  LV UUID                rdYOR3-ETaO-Lc33-L0Si-ke3a-J3dV-qRTuGs
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2023-12-30 2207 +0800
  LV Status              available
  # open                 0
  LV Size                1.07 GiB  # 容量增长为1.07
  Current LE             275  # 增加了25个PE
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:4

或者将VG的空闲容量全部分配给LV

[root@localhost ~]# lvextend -l +100%FREE vgtest2/lvtest2
  Size of logical volume vgtest2/lvtest2 changed from 1.07 GiB (275 extents) to 19.99 GiB (5118 extents).
  Logical volume vgtest2/lvtest2 successfully resized.
[root@localhost ~]# lvdisplay vgtest2/lvtest2
  --- Logical volume ---
  LV Path                /dev/vgtest2/lvtest2
  LV Name                lvtest2
  VG Name                vgtest2
  LV UUID                rdYOR3-ETaO-Lc33-L0Si-ke3a-J3dV-qRTuGs
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2023-12-30 2207 +0800
  LV Status              available
  # open                 0
  LV Size                19.99 GiB  # 容量增长为19.99
  Current LE             5118
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:4

将逻辑卷“lvtest2”挂载

[root@localhost ~]# mkfs.xfs /dev/vgtest2/lvtest2  # 创建xfs文件系统
meta-data=/dev/vgtest2/lvtest2   isize=512    agcount=4, agsize=1310208 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0 inobtcount=0
data     =                       bsize=4096   blocks=5240832, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
[root@localhost ~]# mkdir /data
[root@localhost ~]# mount /dev/vgtest2/lvtest2 /data  # 挂载逻辑卷
[root@localhost ~]# df -Th /data
Filesystem                  Type  Size  Used Avail Use% Mounted on
/dev/mapper/vgtest2-lvtest2 xfs    20G  175M   20G   1% /data

如果想要永久挂载，需要在“/etc/fstab”文件中增加一行配置

[root@localhost ~]# blkid /dev/vgtest2/lvtest2  # 查看逻辑卷的UUID，通过UUID的方式挂载
/dev/vgtest2/lvtest2: UUID="544fae3b-7d08-4090-a6a7-aa5bcc4d9be0" BLOCK_SIZE="512" TYPE="xfs"
[root@localhost ~]# vim /etc/fstab


# 
# /etc/fstab
# Created by anaconda on Wed Nov 29 1550 2023
#
# 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.
#
# After editing this file, run 'systemctl daemon-reload' to update systemd
# units generated from this file.
#
/dev/mapper/rl-root     /                       xfs     defaults        0 0
UUID=9d58ddae-ddae-4a83-8841-4b9863b55ab5 /boot                   xfs     defaults        0 0
/dev/mapper/rl-swap     none                    swap    defaults        0 0
UUID="544fae3b-7d08-4090-a6a7-aa5bcc4d9be0" /data xfs defaults 0 0  # 添加这一行
[root@localhost ~]# mount -a  # 读取“/etc/fstab”配置文件，挂载文件中定义的设备 

现在，假设服务器目录“/data”所涉及的业务量日益增加，而逻辑卷“lvtest2”的空间不足以支撑，需要对它再次进行扩容，我们可以这样做：

因为逻辑卷“lvtest2”关联的卷组是“vgtest2”，而“vgtest2”的所有容量已分配给了“lvtest2”，我们需要先对“vgtest2”进行扩容

新增一些scsi磁盘，如果希望在不重启的情况下让系统识别到新增的硬盘，可以这样做

[root@localhost ~]# ls /sys/class/scsi_host/
host0  host1  host2
[root@localhost ~]# echo "- - -" > /sys/class/scsi_host/host0/scan   # 有多少个目录就对应执行多个目录的命令
[root@localhost ~]# echo "- - -" > /sys/class/scsi_host/host1/scan 
[root@localhost ~]# echo "- - -" > /sys/class/scsi_host/host2/scan 
[root@localhost ~]# ls /sys/class/scsi_device/
1:0:0:0  2:0:0:0  2:0:1:0  2:0:10:0  2:0:2:0  2:0:3:0  2:0:4:0  2:0:5:0  2:0:6:0  2:0:8:0  2:0:9:0
[root@localhost ~]# echo 1 > /sys/class/scsi_device/1:0:0:0/device/rescan   # 有多少个目录就对应执行多个目录的命令
[root@localhost ~]# echo 1 > /sys/class/scsi_device/2:0:0:0/device/rescan 
[root@localhost ~]# echo 1 > /sys/class/scsi_device/2:0:1:0/device/rescan 
[root@localhost ~]# echo 1 > /sys/class/scsi_device/2:0:10:0/device/rescan 
[root@localhost ~]# echo 1 > /sys/class/scsi_device/2:0:2:0/device/rescan 
[root@localhost ~]# echo 1 > /sys/class/scsi_device/2:0:3:0/device/rescan 
[root@localhost ~]# echo 1 > /sys/class/scsi_device/2:0:4:0/device/rescan 
[root@localhost ~]# echo 1 > /sys/class/scsi_device/2:0:5:0/device/rescan 
[root@localhost ~]# echo 1 > /sys/class/scsi_device/2:0:6:0/device/rescan 
[root@localhost ~]# echo 1 > /sys/class/scsi_device/2:0:8:0/device/rescan 
[root@localhost ~]# echo 1 > /sys/class/scsi_device/2:0:9:0/device/rescan 
[root@localhost ~]# lsblk  # 重新扫描后，就可以看到新增的块设备了
NAME                MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda                   8:0    0   50G  0 disk 
├─sda1                8:1    0    1G  0 part /boot
└─sda2                8:2    0   49G  0 part 
  ├─rl-root         253:0    0 45.1G  0 lvm  /
  └─rl-swap         253:1    0  3.9G  0 lvm  [SWAP]
sdb                   8:16   0   10G  0 disk 
└─vgtest-lvtest     253:2    0   10G  0 lvm  
sdc                   8:32   0   10G  0 disk 
└─sdc1                8:33   0    5G  0 part 
  └─vgtest1-lvtest1 253:3    0    3G  0 lvm  
sdd                   8:48   0   10G  0 disk 
└─vgtest2-lvtest2   253:4    0   20G  0 lvm  /data
sde                   8:64   0   10G  0 disk 
└─vgtest2-lvtest2   253:4    0   20G  0 lvm  /data
sdf                   8:80   0   10G  0 disk 
sdg                   8:96   0   10G  0 disk 
sdh                   8:112  0   10G  0 disk 
sdi                   8:128  0   10G  0 disk 
sdj                   8:144  0   10G  0 disk 
sr0                  11:0    1 1024M  0 rom  

首先，我们使用“/dev/sdf”这块磁盘创建PV，用于“vgtest2”的扩容

[root@localhost ~]# pvcreate /dev/sdf
  Physical volume "/dev/sdf" successfully created.
[root@localhost ~]# vgextend vgtest2 /dev/sdf
  Volume group "vgtest2" successfully extended
[root@localhost ~]# vgs vgtest2
  VG      #PV #LV #SN Attr   VSize   VFree  
  vgtest2   3   1   0 wz--n- <29.99g <10.00g  # 现在vgtest2的容量增长为30

然后，对逻辑卷“lvtest2”扩容，将空闲容量全部分配给它

[root@localhost ~]# lvextend -l +100%FREE vgtest2/lvtest2
  Size of logical volume vgtest2/lvtest2 changed from 19.99 GiB (5118 extents) to <29.99 GiB (7677 extents).
  Logical volume vgtest2/lvtest2 successfully resized.

虽然逻辑卷“lvtest2”的容量已扩容至30G，但是挂载的目录仍显示可用容量为20G

[root@localhost ~]# lvs vgtest2/lvtest2
  LV      VG      Attr       LSize   Pool Origin Data%  Meta%  Move Log Cpy%Sync Convert
  lvtest2 vgtest2 -wi-ao---- <29.99g    
[root@localhost ~]# df -Th /data
Filesystem                  Type  Size  Used Avail Use% Mounted on
/dev/mapper/vgtest2-lvtest2 xfs    20G  175M   20G   1% /data

需要对文件系统进行扩容，ext类型的文件系统的扩容命令是“resize2fs”，xfs类型的文件系统扩容命令是xfs_growfs

[root@localhost ~]# xfs_growfs /dev/vgtest2/lvtest2 
meta-data=/dev/mapper/vgtest2-lvtest2 isize=512    agcount=4, agsize=1310208 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0 inobtcount=0
data     =                       bsize=4096   blocks=5240832, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 5240832 to 7861248
[root@localhost ~]# df -Th /data
Filesystem                  Type  Size  Used Avail Use% Mounted on
/dev/mapper/vgtest2-lvtest2 xfs    30G  247M   30G   1% /data    # 容量扩容至30G了

或者，我们可以在扩容逻辑卷的同时，一并把文件系统扩容，只需要在lvextend命令后面加上一个“-r”参数

对“lvtest2”再次进行扩容

[root@localhost ~]# pvcreate /dev/sdg  # 创建PV
  Physical volume "/dev/sdg" successfully created.
[root@localhost ~]# vgextend vgtest2 /dev/sdg # 扩容VG
  Volume group "vgtest2" successfully extended
[root@localhost ~]# lvextend -L +5G -r vgtest2/lvtest2  # 扩容LV，增加5G容量，同时扩容文件系统
  Size of logical volume vgtest2/lvtest2 changed from <29.99 GiB (7677 extents) to <34.99 GiB (8957 extents).
  Logical volume vgtest2/lvtest2 successfully resized.
meta-data=/dev/mapper/vgtest2-lvtest2 isize=512    agcount=6, agsize=1310208 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1    bigtime=0 inobtcount=0
data     =                       bsize=4096   blocks=7861248, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 7861248 to 9171968
[root@localhost ~]# df -Th /data
Filesystem                  Type  Size  Used Avail Use% Mounted on
/dev/mapper/vgtest2-lvtest2 xfs    35G  283M   35G   1% /data  # 容量扩容至35

审核编辑：汤梓红