使用vmbox安装了ubuntu server的虚拟机，分配了50G的磁盘空间，但是使用df命令查看，发现总的磁盘空间不足50G
root@ubuntu1:/home/lyh# df -h
Filesystem Size Used Avail Use% Mounted on
udev 1.9G 0 1.9G 0% /dev
tmpfs 394M 1.1M 393M 1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv 24G 13G 11G 55% /
tmpfs 2.0G 0 2.0G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 2.0G 0 2.0G 0% /sys/fs/cgroup
/dev/loop1 56M 56M 0 100% /snap/core18/2253
/dev/loop0 56M 56M 0 100% /snap/core18/2246
/dev/loop4 68M 68M 0 100% /snap/lxd/21545
/dev/loop3 62M 62M 0 100% /snap/core20/1242
/dev/loop5 68M 68M 0 100% /snap/lxd/21835
/dev/loop6 33M 33M 0 100% /snap/snapd/13640
/dev/loop7 43M 43M 0 100% /snap/snapd/14066
/dev/sda2 976M 203M 707M 23% /boot
tmpfs 394M 0 394M 0% /run/user/1000
/dev/loop8 62M 62M 0 100% /snap/core20/1270
发现 /dev/mapper/ubuntu--vg-ubuntu--lv 只有24个G的空间
查看所有块设备，以及他们之间的依赖关系
root@ubuntu1:/home/lyh# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
loop0 7:0 0 55.5M 1 loop /snap/core18/2246
loop1 7:1 0 55.5M 1 loop /snap/core18/2253
loop3 7:3 0 61.9M 1 loop /snap/core20/1242
loop4 7:4 0 67.3M 1 loop /snap/lxd/21545
loop5 7:5 0 67.2M 1 loop /snap/lxd/21835
loop6 7:6 0 32.5M 1 loop /snap/snapd/13640
loop7 7:7 0 42.2M 1 loop /snap/snapd/14066
loop8 7:8 0 61.9M 1 loop /snap/core20/1270
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 1M 0 part
├─sda2 8:2 0 1G 0 part /boot
└─sda3 8:3 0 49G 0 part
└─ubuntu--vg-ubuntu--lv 253:0 0 24.5G 0 lvm /
sr0 11:0 1 1024M 0 rom
发现sda3实际有50个G的空间，但是 ubuntu--vg-ubuntu--lv 只有24.5个G，剩余的空间并没有显示
查看LVM卷组的信息
root@ubuntu1:/home/lyh# vgdisplay
--- Volume group ---
VG Name ubuntu-vg
System ID
Format lvm2
Metadata Areas 1
Metadata Sequence No 2
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
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 6272 / 24.50 GiB
Free PE / Size 6271 / <24.50 GiB
VG UUID QV4pAN-R1BR-42Ln-Vv4J-58Nb-uniH-0qizNA
发现还有24.5G的 Free空间未分配
lvextend -L 20G /dev/mapper/ubuntu--vg-ubuntu--lv //增大或减小至20G
lvextend -L +10G /dev/mapper/ubuntu--vg-ubuntu--lv //增加10G
lvreduce -L -10G /dev/mapper/ubuntu--vg-ubuntu--lv //减小10G
lvresize -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv //按百分比扩容
resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv //执行调整
例如：在我原有的磁盘上增加10个G
root@ubuntu1:/home/lyh# lvextend -L +10G /dev/mapper/ubuntu--vg-ubuntu--lv
Size of logical volume ubuntu-vg/ubuntu-lv changed from 24.50 GiB (6272 extents) to 34.50 GiB (8832 extents).
Logical volume ubuntu-vg/ubuntu-lv successfully resized.
root@ubuntu1:/home/lyh# resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv
resize2fs 1.45.5 (07-Jan-2020)
Filesystem at /dev/mapper/ubuntu--vg-ubuntu--lv is mounted on /; on-line resizing required
old_desc_blocks = 4, new_desc_blocks = 5
The filesystem on /dev/mapper/ubuntu--vg-ubuntu--lv is now 9043968 (4k) blocks long.
root@ubuntu1:/home/lyh# df -h
Filesystem Size Used Avail Use% Mounted on
udev 1.9G 0 1.9G 0% /dev
tmpfs 394M 1.1M 393M 1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv 34G 13G 20G 39% /
tmpfs 2.0G 0 2.0G 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 2.0G 0 2.0G 0% /sys/fs/cgroup
/dev/loop1 56M 56M 0 100% /snap/core18/2253
/dev/loop0 56M 56M 0 100% /snap/core18/2246
/dev/loop4 68M 68M 0 100% /snap/lxd/21545
/dev/loop3 62M 62M 0 100% /snap/core20/1242
/dev/loop5 68M 68M 0 100% /snap/lxd/21835
/dev/loop6 33M 33M 0 100% /snap/snapd/13640
/dev/loop7 43M 43M 0 100% /snap/snapd/14066
/dev/sda2 976M 203M 707M 23% /boot
tmpfs 394M 0 394M 0% /run/user/1000
/dev/loop8 62M 62M 0 100% /snap/core20/1270
可以看到，/dev/mapper/ubuntu--vg-ubuntu--lv 已经增加了10个G