Ubuntu 磁盘动态分区调整

Lewis

Jan 3, 2024 — 6 min read

当我们调整虚拟机的虚拟硬盘大小或将磁盘映像恢复到更大的磁盘时，Ubuntu检测到的分区的可用空间不会增加，因为分区表没有改变。过去，我们可以借助 .ext4 轻松调整 ext4 根分区的大小resize2fs。然而，当 Ubuntu 使用 LVM 分区作为默认根分区时，事情会变得复杂。

LVM 介绍

逻辑卷管理器（LVM）类似于Windows下的动态磁盘，它可以将不同硬盘上的几个GPT/MBR分区作为一个存储池（LVM称之为Volume Groups，VG），并从这个池中分配空间，然后Linux将将每个空间（LVM 称为逻辑卷，LV）识别为可用分区。

PV、VG、LV 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组成到一起，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。

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

扩展 ubuntu--vg-ubuntu--lv

查看磁盘使用情况

df -hl

Filesystem                         Size  Used Avail Use% Mounted on
tmpfs                              792M  1.7M  790M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   37G   13G   23G  36% /
tmpfs                              3.9G   28K  3.9G   1% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
/dev/sda2                          2.0G  126M  1.7G   7% /boot
/dev/sda1                          1.1G  5.3M  1.1G   1% /boot/efi
ncdata                              39G   39M   39G   1% /mnt/ncdata
overlay                             37G   13G   23G  36% /var/lib/docker/overlay2/06991ebd4b2aa71bad195055f4c25f56505fe8f827f22f255bc63a1efe53094b/merged
tmpfs                              792M  4.0K  792M   1% /run/user/1000

创建分区 sda4，设置为 lvm 类型

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 != 2097151999) 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: 1000 GiB, 1073741824000 bytes, 2097152000 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: 469C7B79-92EE-49A6-B150-E85497A85FF9

Device       Start      End  Sectors  Size Type
/dev/sda1     2048  2203647  2201600    1G EFI System
/dev/sda2  2203648  6397951  4194304    2G Linux filesystem
/dev/sda3  6397952 83884031 77486080 36.9G Linux filesystem

Command (m for help): n
Partition number (4-128, default 4): 4
First sector (83884032-2097151966, default 83884032): 83884032
Last sector, +/-sectors or +/-size{K,M,G,T,P} (83884032-2097151966, default 2097151966): 2097151966

Created a new partition 4 of type 'Linux filesystem' and of size 960 GiB.

Command (m for help): p
Disk /dev/sda: 1000 GiB, 1073741824000 bytes, 2097152000 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: 469C7B79-92EE-49A6-B150-E85497A85FF9

Device        Start        End    Sectors  Size Type
/dev/sda1      2048    2203647    2201600    1G EFI System
/dev/sda2   2203648    6397951    4194304    2G Linux filesystem
/dev/sda3   6397952   83884031   77486080 36.9G Linux filesystem
/dev/sda4  83884032 2097151966 2013267935  960G 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: 1000 GiB, 1073741824000 bytes, 2097152000 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: 469C7B79-92EE-49A6-B150-E85497A85FF9

Device        Start        End    Sectors  Size Type
/dev/sda1      2048    2203647    2201600    1G EFI System
/dev/sda2   2203648    6397951    4194304    2G Linux filesystem
/dev/sda3   6397952   83884031   77486080 36.9G Linux filesystem
/dev/sda4  83884032 2097151966 2013267935  960G Linux LVM

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

查看可用空间

sudo lsblk

NAME                      MAJ:MIN RM  SIZE RO TYPE MOUNTPOINTS
loop0                       7:0    0   45M  1 loop /snap/certbot/3566
loop1                       7:1    0 63.9M  1 loop /snap/core20/2105
loop2                       7:2    0 40.9M  1 loop /snap/snapd/20290
sda                         8:0    0 1000G  0 disk 
├─sda1                      8:1    0    1G  0 part /boot/efi
├─sda2                      8:2    0    2G  0 part /boot
├─sda3                      8:3    0 36.9G  0 part 
│ └─ubuntu--vg-ubuntu--lv 253:0    0 36.9G  0 lvm  /
└─sda4                      8:4    0  960G  0 part 
sdb                         8:16   0 1000G  0 disk 
├─sdb1                      8:17   0   40G  0 part 
└─sdb9                      8:25   0    8M  0 part

将sda4创建成 PV

sudo pvcreate /dev/sda4

Physical volume "/dev/sda4" successfully created.

sudo pvdisplay

--- Physical volume ---
  PV Name               /dev/sda3
  VG Name               ubuntu-vg
  PV Size               <36.95 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              9458
  Free PE               0
  Allocated PE          9458
  PV UUID               TnNwXh-24oI-B948-5AOY-Lv1O-gg8P-0Obn9i
   
  "/dev/sda4" is a new physical volume of "960.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sda4
  VG Name               
  PV Size               960.00 GiB
  Allocatable           NO
  PE Size               0   
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               8SzDuW-QOPe-mS7m-DFgn-HrRX-RK4E-u9ICJZ

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               <36.95 GiB
  PE Size               4.00 MiB
  Total PE              9458
  Alloc PE / Size       9458 / <36.95 GiB
  Free  PE / Size       0 / 0   
  VG UUID               cvhIN3-FiJn-5R27-fId2-q3aF-QSeI-GC2v7e

将 PV 添加到 VG

sudo vgextend ubuntu-vg /dev/sda4

Volume group "ubuntu-vg" successfully extended

sudo vgdisplay

lume 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               996.94 GiB
  PE Size               4.00 MiB
  Total PE              255217
  Alloc PE / Size       9458 / <36.95 GiB
  Free  PE / Size       245759 / <960.00 GiB
  VG UUID               cvhIN3-FiJn-5R27-fId2-q3aF-QSeI-GC2v7e

调整 LV 占用 VG 的全部空间

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

Size of logical volume ubuntu-vg/ubuntu-lv changed from <36.95 GiB (9458 extents) to 996.94 GiB (255217 extents).
  Logical volume ubuntu-vg/ubuntu-lv successfully resized.

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 = 125
The filesystem on /dev/ubuntu-vg/ubuntu-lv is now 261342208 (4k) blocks long.