前言
Logical Volume Manager (LVM) 提供了一种灵活、高效的方式来管理存储资源，使得存储的扩容、缩容和删除变得更加简单。紧接上篇文章LVM的创建，本文将详细介绍如何使用LVM进行这些操作，以帮助企业根据业务需求动态调整存储容量，提高存储资源的利用率。
一、LV扩容
1.1 查看当前lv配置
[root@db1 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
backup klas -wi-a----- <31.81g
root klas -wi-ao---- 65.14g
swap klas -wi-ao---- 2.04g
lv01 vg_01 -wi-ao---- 25.00g
逻辑卷lv01使用的是逻辑卷组vg_01
1.2 查看逻辑卷组vg_01使用情况
[root@db1 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
klas 1 3 0 wz--n- <99.00g 0
vg_01 2 1 0 wz--n- 39.99g 14.99g
vg_01剩余14.99GB
1.3 扩容lv01
1）lvextend扩容
指定扩容容量
lvextend -L +2G vg_01/lv01
Size of logical volume vg_01/lv01 changed from 25.00 GiB (6400 extents) to 27.00 GiB (6912 extents).
Logical volume vg_01/lv01 successfully resized.
查看扩容情况
[root@db1 ~]# lvdisplay /dev/vg_01/lv01
--- Logical volume ---
LV Path /dev/vg_01/lv01
LV Name lv01
VG Name vg_01
LV UUID 4Z9OQ1-d73H-JTKd-HSHO-E4Zy-Pdi0-nSpQGS
LV Write Access read/write
LV Creation host, time db1, 2024-07-02 05:26:25 +0800
LV Status available
# open 1
LV Size 27.00 GiB
Current LE 6912
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:3
2）指定增加的PE个数来对逻辑卷进行扩容
查看PE大小
[root@db1 ~]# vgdisplay vg_01
--- Volume group ---
VG Name vg_01
System ID
Format lvm2
Metadata Areas 2
Metadata Sequence No 3
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 2
Act PV 2
VG Size 39.99 GiB
PE Size 4.00 MiB -->PE大小为4M
Total PE 10238
Alloc PE / Size 6912 / 27.00 GiB
Free PE / Size 3326 / 12.99 GiB
VG UUID VkDVkl-gkSu-eJoF-qC8R-KQcZ-Ux2B-KsdHBG
扩容2G
需要扩容的PE数量：2048/4=512
lvextend -l +512 /dev/vg_01/lv01
查看扩容情况
[root@db1 ~]# lvdisplay /dev/vg_01/lv01
--- Logical volume ---
LV Path /dev/vg_01/lv01
LV Name lv01
VG Name vg_01
LV UUID 4Z9OQ1-d73H-JTKd-HSHO-E4Zy-Pdi0-nSpQGS
LV Write Access read/write
LV Creation host, time db1, 2024-07-02 05:26:25 +0800
LV Status available
# open 1
LV Size 29.00 GiB -->从27GB扩容到29GB
Current LE 7424
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:3
3）将vg所有剩余空间进行扩容
扩容vg所有容量
[root@db1 ~]# lvextend -l +100%FREE /dev/vg_01/lv01
Size of logical volume vg_01/lv01 changed from 29.00 GiB (7424 extents) to 39.99 GiB (10238 extents).
Logical volume vg_01/lv01 successfully resized.
查看扩容情况
[root@db1 ~]# lvdisplay /dev/vg_01/lv01
--- Logical volume ---
LV Path /dev/vg_01/lv01
LV Name lv01
VG Name vg_01
LV UUID 4Z9OQ1-d73H-JTKd-HSHO-E4Zy-Pdi0-nSpQGS
LV Write Access read/write
LV Creation host, time db1, 2024-07-02 05:26:25 +0800
LV Status available
# open 1
LV Size 39.99 GiB -->lv拥有VG所有的容量
Current LE 10238
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 8192
Block device 253:3
1.4 扩容vg
当前所有的vg容量已经全部分配完，此时lv需要扩容，必须要先扩容vg
[root@db1 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
klas 1 3 0 wz--n- <99.00g 0
vg_01 2 1 0 wz--n- 39.99g 0
1) 确认新的磁盘
[root@db1 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 20G 0 disk
└─vg_01-lv01 253:3 0 40G 0 lvm /data
sdb 8:16 0 20G 0 disk
└─vg_01-lv01 253:3 0 40G 0 lvm /data
sdc 8:32 0 20G 0 disk ==》sdc是新添加的磁盘，大小为20g
sr0 11:0 1 4G 0 rom
nvme0n1 259:0 0 100G 0 disk
├─nvme0n1p1 259:1 0 1G 0 part /boot
└─nvme0n1p2 259:2 0 99G 0 part
├─klas-root 253:0 0 65.1G 0 lvm /
├─klas-swap 253:1 0 2G 0 lvm [SWAP]
└─klas-backup 253:2 0 31.8G 0 lvm
2) 创建pv
[root@db1 ~]# pvcreate /dev/sdc
Physical volume "/dev/sdc" successfully created.
3) 添加到vg
[root@db1 ~]# vgextend vg_01 /dev/sdc
Volume group "vg_01" successfully extended
4)分配空间到lv
确认vg剩余空间
[root@db1 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
klas 1 3 0 wz--n- <99.00g 0
vg_01 3 1 0 wz--n- <59.99g <20.00g
添加空间到lv
[root@db1 ~]# lvextend -L +2G vg_01/lv01
Size of logical volume vg_01/lv01 changed from 39.99 GiB (10238 extents) to 41.99 GiB (10750 extents).
Logical volume vg_01/lv01 successfully resized.
确认扩容成功
[root@db1 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
backup klas -wi-a----- <31.81g
root klas -wi-ao---- 65.14g
swap klas -wi-ao---- 2.04g
lv01 vg_01 -wi-ao---- 41.99g
二、LVM缩容
2.1 umount挂载点
--查看挂载点
mount -l
或
df -h
--卸载挂载点
umount /data
如果不卸载文件系统，缩容会提示在线缩容不支持：
[root@db1 ~]# resize2fs /dev/vg_01/lv01 5G
resize2fs 1.45.6 (20-Mar-2020)
Filesystem at /dev/vg_01/lv01 is mounted on /data; on-line resizing required
resize2fs: On-line shrinking not supported
2.2 查看逻辑卷lv01
[root@db1 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
backup klas -wi-a----- <31.81g
root klas -wi-ao---- 65.14g
swap klas -wi-ao---- 2.04g
lv01 vg_01 -wi-a----- 39.99g
2.3 缩容lv01
检查逻辑卷
[root@db1 ~]# e2fsck -f /dev/vg_01/lv01
e2fsck 1.45.6 (20-Mar-2020)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
/lost+found not found. Create<y>? yes
Pass 4: Checking reference counts
Pass 5: Checking group summary information
缩容lv
[root@db1 ~]# resize2fs /dev/vg_01/lv01 5G
resize2fs 1.45.6 (20-Mar-2020)
Resizing the filesystem on /dev/vg_01/lv01 to 1310720 (4k) blocks.
The filesystem on /dev/vg_01/lv01 is now 1310720 (4k) blocks long.
[root@db1 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
backup klas -wi-a----- <31.81g
root klas -wi-ao---- 65.14g
swap klas -wi-ao---- 2.04g
lv01 vg_01 -wi-a----- 39.99g
[root@db1 ~]#
[root@db1 ~]# lvreduce -L 5G /dev/vg_01/lv01 5G
Command does not accept argument: 5G.
[root@db1 ~]# lvreduce -L 5G /dev/vg_01/lv01
WARNING: Reducing active logical volume to 5.00 GiB.
THIS MAY DESTROY YOUR DATA (filesystem etc.)
Do you really want to reduce vg_01/lv01? [y/n]:
WARNING: Invalid input ''.
Do you really want to reduce vg_01/lv01? [y/n]: y
Size of logical volume vg_01/lv01 changed from 39.99 GiB (10238 extents) to 5.00 GiB (1280 extents).
Logical volume vg_01/lv01 successfully resized.
确认缩容成功
[root@db1 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
backup klas -wi-a----- <31.81g
root klas -wi-ao---- 65.14g
swap klas -wi-ao---- 2.04g
lv01 vg_01 -wi-a----- 5.00g
[root@db1 ~]#
2.4 重新挂载
mount挂载
mount -a
或
mount /dev/vg_01/lv01 /data
检查确认挂载点
df -Th
三、LVM删除
3.1 卸载文件系统
umount /dev/data
3.2 删除lv
[root@db1 ~]# lvremove /dev/vg_01/lv01
Do you really want to remove active logical volume vg_01/lv01? [y/n]: y
Logical volume "lv01" successfully removed
3.3 删除vg
[root@db1 ~]# vgremove vg_01
Volume group "vg_01" successfully removed
3.4 删除pv
[root@db1 ~]# pvremove /dev/sda /dev/sdb /dev/sdc
Labels on physical volume "/dev/sda" successfully wiped.
Labels on physical volume "/dev/sdb" successfully wiped.
Labels on physical volume "/dev/sdc" successfully wiped.
或
[root@db1 ~]# pvremove /dev/sd{a,b,c}
四、结语
LVM作为一项成熟且强大的存储管理技术，为企业和个人提供了灵活、高效、可靠的存储解决方案。通过本文的介绍，相信您已经对LVM有了更深入的理解，并掌握了如何在实际环境中管理和优化LVM。随着技术的发展，LVM将继续发挥其在存储领域的核心作用，帮助企业构建更加稳健、可扩展的存储基础设施，以应对未来的挑战。
