Ubuntu Linux 动态调整分区空间
1. 背景
用了一段时间后，发现 Ubuntu 空间太小了不够用了。于是扩容了硬盘大小，同时需要对分区进行调整来进行扩容。
系统采用的 LVM(Logical Volume Manager)的方式进行管理的。
2. 处理
这里分两种情况进行处理：
- LV(Logical Volume) 没有用尽 VG(Volume Group)。
- VG(Volume Group) 没有用尽 PV(Physical Volume)，或者 PV(Physical Volume) 没有关联物理分区。
2.1 LV 使用全部 VG
可以看到 / 由 /dev/mapper/ubuntu--vg-ubuntu--lv 挂载：
$ df -hl
Filesystem Size Used Avail Use% Mounted on
tmpfs 196M 1.4M 195M 1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv 9.8G 7.5G 1.8G 81% /
tmpfs 980M 16K 980M 1% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
/dev/sda2 1.8G 127M 1.5G 8% /boot
tmpfs 196M 4.0K 196M 1% /run/user/1000
ubuntu--vg-ubuntu--lv 使用的是 sda3 分区，而 sda3 总共 18.2G，ubuntu--vg-ubuntu--lv 只用了 10G:
$ sudo lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
fd0 2:0 1 4K 0 disk
loop0 7:0 0 79.9M 1 loop /snap/lxd/22923
loop1 7:1 0 62M 1 loop /snap/core20/1587
loop2 7:2 0 47M 1 loop /snap/snapd/16292
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 1M 0 part
├─sda2 8:2 0 1.8G 0 part /boot
└─sda3 8:3 0 18.2G 0 part
└─ubuntu--vg-ubuntu--lv 253:0 0 10G 0 lvm /
# VG ubuntu-vg 剩余 8.22G
$ sudo vgdisplay -A
--- 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 18.22 GiB
PE Size 4.00 MiB
Total PE 4665
Alloc PE / Size 2560 / 10.00 GiB
Free PE / Size 2105 / 8.22 GiB
VG UUID gHs11o-PLvl-3cw4-SIax-mcw6-7RCx-D4BEpo
两条命令调整 LV 占用 VG 的全部空间：
$ sudo lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv
$ sudo resize2fs /dev/ubuntu-vg/ubuntu-lv
结果，扩容成功：
$ sudo lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
fd0 2:0 1 4K 0 disk
loop0 7:0 0 79.9M 1 loop /snap/lxd/22923
loop1 7:1 0 62M 1 loop /snap/core20/1587
loop2 7:2 0 47M 1 loop /snap/snapd/16292
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 1M 0 part
├─sda2 8:2 0 1.8G 0 part /boot
└─sda3 8:3 0 18.2G 0 part
└─ubuntu--vg-ubuntu--lv 253:0 0 18.2G 0 lvm /
2.2 VG 关联物理分区进行扩容
这里以不损坏数据为前提，所以就不对原分区 /dev/sda3进行调整了。而是采用将磁盘可用空间创建一个新的 /dev/sda4 分区，然后去关联 VG，毕竟 LVM 非常灵活。
下面对新增加的 30GB 进行处理。
创建分区 sda4，将设置为 lvm 类型：
$ sudo fdisk /dev/sda
==> Command (m for help): p
Disk /dev/sda: 50 GiB, 53687091200 bytes, 104857600 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: 3A0A0460-1FC2-46FF-A278-3299E8F2B745
Device Start End Sectors Size Type
/dev/sda1 2048 4095 2048 1M BIOS boot
/dev/sda2 4096 3719167 3715072 1.8G Linux filesystem
/dev/sda3 3719168 41940991 38221824 18.2G Linux filesystem
===> Command (m for help): n
Partition number (4-128, default 4):
First sector (41940992-104857566, default 41940992):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (41940992-104857566, default 104857566):
Created a new partition 4 of type 'Linux filesystem' and of size 30 GiB.
===> Command (m for help): p
Disk /dev/sda: 50 GiB, 53687091200 bytes, 104857600 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: 3A0A0460-1FC2-46FF-A278-3299E8F2B745
Device Start End Sectors Size Type
/dev/sda1 2048 4095 2048 1M BIOS boot
/dev/sda2 4096 3719167 3715072 1.8G Linux filesystem
/dev/sda3 3719168 41940991 38221824 18.2G Linux filesystem
/dev/sda4 41940992 104857566 62916575 30G Linux filesystem
===> Command (m for help): t
===> Partition number (1-4, default 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: 50 GiB, 53687091200 bytes, 104857600 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: 3A0A0460-1FC2-46FF-A278-3299E8F2B745
Device Start End Sectors Size Type
/dev/sda1 2048 4095 2048 1M BIOS boot
/dev/sda2 4096 3719167 3715072 1.8G Linux filesystem
/dev/sda3 3719168 41940991 38221824 18.2G Linux filesystem
/dev/sda4 41940992 104857566 62916575 30G Linux LVM
===> Command (m for help): w
The partition table has been altered.
Syncing disks.
可以看到 sda4 创建成功，并使用所有可用空间：
$ sudo lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
fd0 2:0 1 4K 0 disk
loop0 7:0 0 79.9M 1 loop /snap/lxd/22923
loop1 7:1 0 62M 1 loop /snap/core20/1587
loop2 7:2 0 47M 1 loop /snap/snapd/16292
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 1M 0 part
├─sda2 8:2 0 1.8G 0 part /boot
├─sda3 8:3 0 18.2G 0 part
│ └─ubuntu--vg-ubuntu--lv 253:0 0 18.2G 0 lvm /
└─sda4 8:4 0 30G 0 part
将 sda4创建成 PV(Physical Volume)：
$ sudo pvcreate /dev/sda4
Physical volume "/dev/sda4" successfully created.
$ sudo pvdisplay
--- Physical volume ---
PV Name /dev/sda3
VG Name ubuntu-vg
PV Size <18.23 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 4665
Free PE 0
Allocated PE 4665
PV UUID vO0lgC-X0bG-nUat-kevg-FONv-OpNh-qwY5zF
"/dev/sda4" is a new physical volume of "30.00 GiB"
--- NEW Physical volume ---
PV Name /dev/sda4
VG Name
PV Size 30.00 GiB
Allocatable NO
PE Size 0
Total PE 0
Free PE 0
Allocated PE 0
PV UUID A87gcC-J2mc-3jPD-4emh-8Ute-VQ52-Ceg7zu
将 sda4扩容到当前的 VG：
# 查看当前 VG
$ 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 18.22 GiB
PE Size 4.00 MiB
Total PE 4665
Alloc PE / Size 4665 / 18.22 GiB
Free PE / Size 0 / 0
VG UUID gHs11o-PLvl-3cw4-SIax-mcw6-7RCx-D4BEpo
# 将 PV 添加到 VG
$ sudo vgextend ubuntu-vg /dev/sda4
# 扩展成功
$ 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 <48.22 GiB
PE Size 4.00 MiB
Total PE 12344
Alloc PE / Size 4665 / 18.22 GiB
Free PE / Size 7679 / <30.00 GiB
VG UUID gHs11o-PLvl-3cw4-SIax-mcw6-7RCx-D4BEpo
接下来就同 2.1 的操作了：
$ sudo lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv
$ sudo resize2fs /dev/ubuntu-vg/ubuntu-lv
$ sudo lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
fd0 2:0 1 4K 0 disk
loop0 7:0 0 79.9M 1 loop /snap/lxd/22923
loop1 7:1 0 62M 1 loop /snap/core20/1587
loop2 7:2 0 47M 1 loop /snap/snapd/16292
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 1M 0 part
├─sda2 8:2 0 1.8G 0 part /boot
├─sda3 8:3 0 18.2G 0 part
│ └─ubuntu--vg-ubuntu--lv 253:0 0 48.2G 0 lvm /
└─sda4 8:4 0 30G 0 part
└─ubuntu--vg-ubuntu--lv 253:0 0 48.2G 0 lvm /