1、虚拟机关机通过管理界面给磁盘扩容。

root@curtis:/home/curtis/git_code# pvdisplay
  --- Physical volume ---
  PV Name               /dev/vda3
  VG Name               ubuntu-vg
  PV Size               <239.00 GiB / not usable 0
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              61183
  Free PE               0
  Allocated PE          61183
  PV UUID               WoCzb3-a3jy-yV23-gOau-UeiA-K62x-petsV2

2、虚拟机启动之后查看磁盘容量，并且使用gparted更新分区表。

root@curtis:~# lsblk
NAME                      MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sr0                        11:0    1 1024M  0 rom
vda                       252:0    0  512G  0 disk
├─vda1                    252:1    0    1M  0 part
├─vda2                    252:2    0    1G  0 part /boot
└─vda3                    252:3    0  239G  0 part
  └─ubuntu--vg-ubuntu--lv 253:0    0  239G  0 lvm  /

root@curtis:~# parted /dev/vda
GNU Parted 3.2
Using /dev/vda
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) print
Warning: Not all of the space available to /dev/vda appears to be used, you can fix the GPT to use all of the space (an extra 570425344 blocks) or continue with
the current setting?
Fix/Ignore? Fix
Model: Virtio Block Device (virtblk)
Disk /dev/vda: 550GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:

Number  Start   End     Size    File system  Name  Flags
 1      1049kB  2097kB  1049kB                     bios_grub
 2      2097kB  1076MB  1074MB  ext4
 3      1076MB  258GB   257GB

3、cfdisk给磁盘扩容，选择到需要扩容的分区之后，选择resize，然后把所有剩余可用磁盘容量分配给目标分区。

4、使用pvresize命令给物理卷扩容，扩容完成之后可以看到卷组空闲容量增加，因为对应物理卷属于VG。

root@curtis:~# pvresize /dev/vda3
  Physical volume "/dev/vda3" changed
  1 physical volume(s) resized / 0 physical volume(s) not resized
root@curtis:~# pvdisplay
  --- Physical volume ---
  PV Name               /dev/vda3
  VG Name               ubuntu-vg
  PV Size               <511.00 GiB / not usable 16.50 KiB
  Allocatable           yes
  PE Size               4.00 MiB
  Total PE              130815
  Free PE               69632
  Allocated PE          61183
  PV UUID               WoCzb3-a3jy-yV23-gOau-UeiA-K62x-petsV2

root@curtis:~# vgdisplay
  --- Volume group ---
  VG Name               ubuntu-vg
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  8
  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               <511.00 GiB
  PE Size               4.00 MiB
  Total PE              130815
  Alloc PE / Size       61183 / <239.00 GiB
  Free  PE / Size       69632 / 272.00 GiB	# 卷组剩余可用磁盘
  VG UUID               za8fRc-LJLO-RZnk-rgC7-RWzi-EdFP-b3CL94

5、将卷组全部可用的磁盘容量分配给逻辑卷。

root@curtis:~# df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               7.8G     0  7.8G   0% /dev
tmpfs                              1.6G  1.1M  1.6G   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv  235G  202G   23G  90% /
tmpfs                              7.9G     0  7.9G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              7.9G     0  7.9G   0% /sys/fs/cgroup
/dev/vda2                          974M  171M  736M  19% /boot
tmpfs                              1.6G     0  1.6G   0% /run/user/0
overlay                            235G  202G   23G  90% /var/lib/docker/overlay2/87855dc438df45c79803a622f203e2d018c199462d41427c35a30a7b24fd8327/merged
overlay                            235G  202G   23G  90% /var/lib/docker/overlay2/077eda580493c22cc08d5e7ab562d792498872291914e12040b35a54e52f1fde/merged
overlay                            235G  202G   23G  90% /var/lib/docker/overlay2/519095e6c98bb655d0a74390704dd2091b4f3274dc9de284a085cb6b6bb8a8f4/merged

root@curtis:~# lvextend -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv	# 可以根据自己的需求分配空间
  Size of logical volume ubuntu-vg/ubuntu-lv changed from <239.00 GiB (61183 extents) to <511.00 GiB (130815 extents).
  Logical volume ubuntu-vg/ubuntu-lv successfully resized.
root@curtis:~# df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               7.8G     0  7.8G   0% /dev
tmpfs                              1.6G  1.1M  1.6G   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv  235G  202G   23G  90% /
tmpfs                              7.9G     0  7.9G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              7.9G     0  7.9G   0% /sys/fs/cgroup
/dev/vda2                          974M  171M  736M  19% /boot
tmpfs                              1.6G     0  1.6G   0% /run/user/0
overlay                            235G  202G   23G  90% /var/lib/docker/overlay2/87855dc438df45c79803a622f203e2d018c199462d41427c35a30a7b24fd8327/merged
overlay                            235G  202G   23G  90% /var/lib/docker/overlay2/077eda580493c22cc08d5e7ab562d792498872291914e12040b35a54e52f1fde/merged
overlay                            235G  202G   23G  90% /var/lib/docker/overlay2/519095e6c98bb655d0a74390704dd2091b4f3274dc9de284a085cb6b6bb8a8f4/merged

root@curtis:~# resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv
resize2fs 1.44.1 (24-Mar-2018)
Filesystem at /dev/mapper/ubuntu--vg-ubuntu--lv is mounted on /; on-line resizing required
old_desc_blocks = 30, new_desc_blocks = 64
The filesystem on /dev/mapper/ubuntu--vg-ubuntu--lv is now 133954560 (4k) blocks long.

root@curtis:~# df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               7.8G     0  7.8G   0% /dev
tmpfs                              1.6G  1.1M  1.6G   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv  503G  202G  280G  42% /
tmpfs                              7.9G     0  7.9G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              7.9G     0  7.9G   0% /sys/fs/cgroup
/dev/vda2                          974M  171M  736M  19% /boot
tmpfs                              1.6G     0  1.6G   0% /run/user/0
overlay                            503G  202G  280G  42% /var/lib/docker/overlay2/87855dc438df45c79803a622f203e2d018c199462d41427c35a30a7b24fd8327/merged
overlay                            503G  202G  280G  42% /var/lib/docker/overlay2/077eda580493c22cc08d5e7ab562d792498872291914e12040b35a54e52f1fde/merged
overlay                            503G  202G  280G  42% /var/lib/docker/overlay2/519095e6c98bb655d0a74390704dd2091b4f3274dc9de284a085cb6b6bb8a8f4/merged

参考文档：https://packetpushers.net/blog/ubuntu-extend-your-default-lvm-space/