虚拟机磁盘大小变更后的Ubuntu动态分区调整

家人们，今天我们来分享一下关于虚拟机磁盘大小变更后，在Ubuntu操作系统中如何进行动态分区调整的技巧。随着虚拟化技术的发展，虚拟机已经成为许多开发者和系统管理员的首选工具之一。在使用虚拟机过程中，可能会遇到需要扩展磁盘容量的情况，而Ubuntu作为一种常见的操作系统，我们将介绍如何动态调整分区以适应磁盘大小的变更。

pv、lv、vg 介绍

• PV（Phsical Volume，物理卷），PV是VG的组成部分，由分区构成，多块盘的时候，可以把一块盘格式化成一个主分区，然后用这个分区做成一个PV，只有一块盘的时候，可以这块盘的某一个分区做成一个PV，实际上一个PV就一个分区。

• VG（Volume Group， 卷组），有若干个PV组成，作用就是将PV组成到以前，然后再重新划分空间。

• LV（Logical Volume，逻辑卷），LV就是从VG中划分出来的卷，LV的使用要比PV灵活的多，可以在空间不够的情况下，增加空间。

可以说成是PV就是硬盘,而VG就是管理硬盘的操作系统,而LV就是操作系统分出来的各个分区.
PV->VG->LV-> 文件系统使用(挂载到某个目录)
硬盘或分区做成pv，然后将pv或多个pv建立vg，vg上建立lv,其模型如下

命令集合

PV

pvcreate :根据物理盘,创建pv

pvscan :查询目前系统里的pv

pvdisplay:显示pv的状态

pvremove:将pv属性移除

VG

vgcreate:创建vg

vgscan:查找当前系统里面的vg

vgdisplay:显示当前系统vg的状态

vgextend:给vg添加额外的pv

vgreduce:在vg内删除pv

vgchange:设置vg是否是启动状态(active)

vgremove:删除一个vg

LV

lvcreate:创建lv

lvscan:查询当前系统的lv

lvdisplay:显示lv的属性

lvextend:给lv添加容量

lvredurce:给lv减少容量

lvremove:删除一个lv

lvresize:对lv大小的容量进行调整

实战案例

1. 查看文件系统的磁盘空间使用情况

df -hl

Filesystem                         Size  Used Avail Use% Mounted on
tmpfs                              791M  2.2M  789M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   38G   26G   11G  72% /
tmpfs                              3.9G     0  3.9G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
/dev/sda2                          2.0G  253M  1.6G  14% /boot
tmpfs                              791M  4.0K  791M   1% /run/user/1000

可以看到 / 由 /dev/mapper/ubuntu--vg-ubuntu--lv 挂载

1. 创建分区 sda4，将设置为 lvm 类型：

sudo fdisk /dev/sda

xiuji@xiuji:~$ sudo fdisk /dev/sda

Welcome to fdisk (util-linux 2.37.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

GPT PMBR size mismatch (83886079 != 209715199) will be corrected by write.
This disk is currently in use - repartitioning is probably a bad idea.
It's recommended to umount all file systems, and swapoff all swap
partitions on this disk.


Command (m for help): p

Disk /dev/sda: 100 GiB, 107374182400 bytes, 209715200 sectors
Disk model: VMware Virtual S
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: gpt
Disk identifier: D80D8A91-AB36-4BB8-A669-783F46148D68

Device       Start      End  Sectors Size Type
/dev/sda1     2048     4095     2048   1M BIOS boot
/dev/sda2     4096  4198399  4194304   2G Linux filesystem
/dev/sda3  4198400 83884031 79685632  38G Linux filesystem

Command (m for help): n
Partition number (4-128, default 4): 4
First sector (83884032-209715166, default 83884032): 83884032
Last sector, +/-sectors or +/-size{K,M,G,T,P} (83884032-209715166, default 209715166): 104857583

Created a new partition 4 of type 'Linux filesystem' and of size 10 GiB.

Command (m for help): p
Disk /dev/sda: 100 GiB, 107374182400 bytes, 209715200 sectors
Disk model: VMware Virtual S
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: gpt
Disk identifier: D80D8A91-AB36-4BB8-A669-783F46148D68

Device        Start       End  Sectors Size Type
/dev/sda1      2048      4095     2048   1M BIOS boot
/dev/sda2      4096   4198399  4194304   2G Linux filesystem
/dev/sda3   4198400  83884031 79685632  38G Linux filesystem
/dev/sda4  83884032 104857583 20973552  10G Linux filesystem

Command (m for help): t
Partition number (1-4, default 4): 4
Partition type or alias (type L to list all): lvm

Changed type of partition 'Linux filesystem' to 'Linux LVM'.

Command (m for help): p
Disk /dev/sda: 100 GiB, 107374182400 bytes, 209715200 sectors
Disk model: VMware Virtual S
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: gpt
Disk identifier: D80D8A91-AB36-4BB8-A669-783F46148D68

Device        Start       End  Sectors Size Type
/dev/sda1      2048      4095     2048   1M BIOS boot
/dev/sda2      4096   4198399  4194304   2G Linux filesystem
/dev/sda3   4198400  83884031 79685632  38G Linux filesystem
/dev/sda4  83884032 104857583 20973552  10G Linux LVM

Command (m for help): w
The partition table has been altered.
Syncing disks.

1. sda4 创建成功，查看所有可用空间：

sudo lsblk

xiuji@xiuji:~$ sudo lsblk
NAME                      MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
loop0                       7:0    0  63.4M  1 loop /snap/core20/1950
loop1                       7:1    0  53.3M  1 loop /snap/snapd/19457
loop2                       7:2    0  53.3M  1 loop /snap/snapd/19361
loop3                       7:3    0  63.5M  1 loop /snap/core20/1891
loop4                       7:4    0 111.9M  1 loop /snap/lxd/24322
sda                         8:0    0   100G  0 disk
├─sda1                      8:1    0     1M  0 part
├─sda2                      8:2    0     2G  0 part /boot
├─sda3                      8:3    0    38G  0 part
│ └─ubuntu--vg-ubuntu--lv 253:0    0    38G  0 lvm  /
└─sda4                      8:4    0    10G  0 part
sr0                        11:0    1   1.8G  0 rom

1. 将 sda4创建成 PV(Physical Volume)：

sudo pvcreate /dev/sda4

xiuji@xiuji:~$ sudo pvcreate /dev/sda4
  Physical volume "/dev/sda4" successfully created.

sudo pvdisplay

xiuji@xiuji:~$ sudo pvdisplay
  --- Physical volume ---
  PV Name               /dev/sda3
  VG Name               ubuntu-vg
  PV Size               <38.00 GiB / not usable 0
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              9727
  Free PE               0
  Allocated PE          9727
  PV UUID               qtpZ00-5KSl-HJr3-GCcf-Ki6B-eQP8-pcO6oH

  "/dev/sda4" is a new physical volume of "10.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sda4
  VG Name
  PV Size               10.00 GiB
  Allocatable           NO
  PE Size               0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               eKegVq-phGh-jZ51-p08D-go8S-fFvt-8DLU62

1. 查看当前 VG

   sudo vgdisplay

xiuji@xiuji:~$  sudo vgdisplay
  --- Volume group ---
  VG Name               ubuntu-vg
  System ID
  Format                lvm2
  Metadata Areas        1
  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                1
  Act PV                1
  VG Size               <38.00 GiB
  PE Size               4.00 MiB
  Total PE              9727
  Alloc PE / Size       9727 / <38.00 GiB
  Free  PE / Size       0 / 0
  VG UUID               vy0kkj-d2tU-Izec-RFY0-1Nmx-cReb-3Kx2S7

1. 将 PV 添加到 VG

   sudo vgextend ubuntu-vg /dev/sda4

xiuji@xiuji:~$ sudo vgextend ubuntu-vg /dev/sda4
  Volume group "ubuntu-vg" successfully extende

sudo vgdisplay

xiuji@xiuji:~$ sudo vgdisplay
  --- Volume group ---
  VG Name               ubuntu-vg
  System ID
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  4
  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               47.99 GiB
  PE Size               4.00 MiB
  Total PE              12286
  Alloc PE / Size       9727 / <38.00 GiB
  Free  PE / Size       2559 / <10.00 GiB
  VG UUID               vy0kkj-d2tU-Izec-RFY0-1Nmx-cReb-3Kx2S7

1. 块设备（block devices）的信息

   sudo lsblk

xiuji@xiuji:~$ sudo lsblk
NAME                      MAJ:MIN RM   SIZE RO TYPE MOUNTPOINTS
loop0                       7:0    0  63.4M  1 loop /snap/core20/1950
loop1                       7:1    0  53.3M  1 loop /snap/snapd/19457
loop2                       7:2    0  53.3M  1 loop /snap/snapd/19361
loop3                       7:3    0  63.5M  1 loop /snap/core20/1891
loop4                       7:4    0 111.9M  1 loop /snap/lxd/24322
sda                         8:0    0   100G  0 disk
├─sda1                      8:1    0     1M  0 part
├─sda2                      8:2    0     2G  0 part /boot
├─sda3                      8:3    0    38G  0 part
│ └─ubuntu--vg-ubuntu--lv 253:0    0    38G  0 lvm  /
└─sda4                      8:4    0    10G  0 part
sr0                        11:0    1   1.8G  0 rom

1. 调整 LV 占用 VG 的全部空间

sudo lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv

xiuji@xiuji:~$ sudo lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv
  Size of logical volume ubuntu-vg/ubuntu-lv changed from <38.00 GiB (9727 extents) to 47.99 GiB (12286 extents).
  Logical volume ubuntu-vg/ubuntu-lv successfully resized.

sudo resize2fs /dev/ubuntu-vg/ubuntu-lv

xiuji@xiuji:~$ sudo resize2fs /dev/ubuntu-vg/ubuntu-lv
resize2fs 1.46.5 (30-Dec-2021)
Filesystem at /dev/ubuntu-vg/ubuntu-lv is mounted on /; on-line resizing required
old_desc_blocks = 5, new_desc_blocks = 6
The filesystem on /dev/ubuntu-vg/ubuntu-lv is now 12580864 (4k) blocks long.

1. 查看文件系统的磁盘空间使用情况

   df -hl

xiuji@xiuji:~$ df -hl
Filesystem                         Size  Used Avail Use% Mounted on
tmpfs                              791M  2.2M  789M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   48G   26G   20G  57% /
tmpfs                              3.9G     0  3.9G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
/dev/sda2                          2.0G  253M  1.6G  14% /boot
tmpfs                              791M  4.0K  791M   1% /run/user/1000

可以看到我们/dev/mapper/ubuntu--vg-ubuntu--lv调整了10G的大小已经生效了