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Ubuntu 在线扩盘

目录

  1. Ubuntu 在线扩盘
    1. 扩展已有磁盘大小
      1. 扩展方式1：扩展已有分区大小
        1. 删除并扩展root分区
        2. 将新的分区加入 LVM
    2. ext4 扩展
    3. 检查
  2. 参考资料

扩展已有磁盘大小

这种方式一般适用于虚拟化环境，在虚拟化环境中可以直接编辑虚拟机已有 vmdk 的大小，之后可以将磁盘新增的空间加到已有分区或者 lvm。

扩展前磁盘大小 50G，sda3 只有 48.2G

root@ubuntu:~# fdisk -l

Disk /dev/sda: 50 GiB, 53687091200 bytes, 104857600 sectors
Disk model: Virtual disk
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: 7F9F6180-639F-4735-AC8A-0ACB2A1E6D44

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 104857566 101138399 48.2G Linux filesystem

进行下列操作前，请先为虚拟机做快照！！

在虚拟化环境中扩大原有磁盘的大小，增加到 200 G：

image-20240329114539848

运行下列命令查看有哪些 SCSI 设备，下图中 scsi32 为硬盘，scsi2 为 CD rom

cat /proc/scsi/scsi | egrep -i 'Host:'
Host: scsi2 Channel: 00 Id: 00 Lun: 00
Host: scsi32 Channel: 00 Id: 00 Lun: 00

可以运行下列命令进一步确认 scsi 号和设备的关联关系

#查看所有 scsi 
ls /sys/class/scsi_device/
2:0:0:0  32:0:0:0

cat /sys/class/scsi_device/32\:0\:0\:0/device/model
Virtual disk

cat /sys/class/scsi_device/2\:0\:0\:0/device/model
VMware SATA CD00

运行下列命令扫描（修改硬盘大小后使用此命令扫描）

echo 1 > /sys/class/scsi_device/32\:0\:0\:0/device/rescan

运行下列命令扫描（给 VM 添加新硬盘后使用此命令扫描）

echo "- - -" > /sys/class/scsi_host/host32/scan

#扫描后，检测到 sda 已经为 200G
[root@centos1 ~]# fdisk -l

GPT PMBR size mismatch (104857599 != 419430399) will be corrected by write.
The backup GPT table is not on the end of the device. This problem will be corrected by write.

Disk /dev/sda: 200 GiB, 214748364800 bytes, 419430400 sectors
Disk model: Virtual disk
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: 7F9F6180-639F-4735-AC8A-0ACB2A1E6D44

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 104857566 101138399 48.2G Linux filesystem

扩展方式1：扩展已有分区大小

这种方式的步骤大致是：

  • 删除root分区的分区表
  • 新建并扩展root分区
  • （如有LVM时）将新分区加到 LVM

删除并扩展root分区

root@ubuntu:~# fdisk /dev/sda

Welcome to fdisk (util-linux 2.34).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

GPT PMBR size mismatch (104857599 != 419430399) will be corrected by write.
The backup GPT table is not on the end of the device. This problem will be corrected by write.
#按 p 查看当前的配置，可以看到/dev/sda3的End sector为419430400
Command (m for help): p

Disk /dev/sda: 200 GiB, 214748364800 bytes, 419430400 sectors
Disk model: Virtual disk
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: 7F9F6180-639F-4735-AC8A-0ACB2A1E6D44

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 104857566 101138399 48.2G Linux filesystem

#删除分区 3，即删除root分区
Command (m for help): d
Partition number (1-3, default 3):

Partition 3 has been deleted.

#新建root分区
Command (m for help): n
Partition number (3-128, default 3):
First sector (3719168-419430366, default 3719168):
#这里默认会使用最大，保持默认即可。如果想增加一定的容量，可以使用“+10G”来表示
Last sector, +/-sectors or +/-size{K,M,G,T,P} (3719168-419430366, default 419430366):
#分区号码，使用3（和之前一样）
Created a new partition 3 of type 'Linux filesystem' and of size 198.2 GiB.
Partition #3 contains a LVM2_member signature.

# 保留 lvm 的 signature，非常重要！
Do you want to remove the signature? [Y]es/[N]o: n
#查看设置正确
Command (m for help): p

Disk /dev/sda: 200 GiB, 214748364800 bytes, 419430400 sectors
Disk model: Virtual disk
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: 7F9F6180-639F-4735-AC8A-0ACB2A1E6D44

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 419430366 415711199 198.2G Linux filesystem
#输入w保存配置
Command (m for help): w
The partition table has been altered.
Syncing disks.

以上配置仅更改了分区表，但kernel还不知道变化，输入下列命令更新。

 partprobe /dev/sda

将新的分区加入 LVM

如果系统也配置了LVM，可以将扩展后的分区直接加到 LVM。

查看当前 LVM 的 PV：

#看到当前大小为48G
root@ubuntu:~# vgdisplay
  --- Volume group ---
  VG Name               ubuntu-vg
  System ID
  Format                lvm2
  Metadata Areas        1
  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                1
  Act PV                1
  VG Size               48.22 GiB
  PE Size               4.00 MiB
  Total PE              12345
  Alloc PE / Size       12345 / 48.22 GiB
  Free  PE / Size       0 / 0
  VG UUID               26Hlwh-RWrE-KTiP-juWl-J3FF-f7HV-llefz1

通过 pvresize 扩大 pv

root@ubuntu:~# pvresize /dev/sda3
  Physical volume "/dev/sda3" changed
  1 physical volume(s) resized or updated / 0 physical volume(s) not resized
  
root@ubuntu:~#  pvdisplay
  --- Physical volume ---
  PV Name               /dev/sda3
  VG Name               ubuntu-vg
  PV Size               <198.23 GiB / not usable 2.98 MiB
  Allocatable           yes
  PE Size               4.00 MiB
  Total PE              50745
  Free PE               38400
  Allocated PE          12345
  PV UUID               kmPW5f-JsMr-0plS-mfhd-MXZB-SG7w-51fzqj

查看当前 lv 大小

root@ubuntu:~# lvdisplay
  --- Logical volume ---
  LV Path                /dev/ubuntu-vg/ubuntu-lv
  LV Name                ubuntu-lv
  VG Name                ubuntu-vg
  LV UUID                rQwVJr-fcBV-DFdQ-eR2S-Pvsw-2h1l-daLQEC
  LV Write Access        read/write
  LV Creation host, time ubuntu-server, 2023-02-21 10:09:26 +0000
  LV Status              available
  # open                 1
  LV Size                48.22 GiB
  Current LE             12345
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0

通过 lvextend 扩展 lv大小，命令格式为：lvextend LV-name PV-name

root@ubuntu:~# lvextend  /dev/ubuntu-vg/ubuntu-lv /dev/sda3
  Size of logical volume ubuntu-vg/ubuntu-lv changed from 48.22 GiB (12345 extents) to 198.22 GiB (50745 extents).
  Logical volume ubuntu-vg/ubuntu-lv successfully resized.
  
#也可以通过lvresize调整lv大小
lvresize /dev/ubuntu-vg/ubuntu-lv /dev/sda3

ext4 扩展

此处 lv 使用的是 ext4 格式分区，可以用下列命令扩展分区：

root@ubuntu:~# 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 = 7, new_desc_blocks = 25
The filesystem on /dev/mapper/ubuntu--vg-ubuntu--lv is now 51962880 (4k) blocks long.

检查

通过 df 查看 / 分区已经成功扩展

root@ubuntu:~# df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                                16G     0   16G   0% /dev
tmpfs                              3.2G  1.3M  3.2G   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv  195G   15G  173G   8% /
tmpfs                               16G     0   16G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                               16G     0   16G   0% /sys/fs/cgroup
/dev/sda2                          1.8G  106M  1.5G   7% /boot
/dev/loop0                          62M   62M     0 100% /snap/core20/1611
/dev/loop1                          68M   68M     0 100% /snap/lxd/22753
/dev/loop2                          47M   47M     0 100% /snap/snapd/16292
tmpfs                              3.2G     0  3.2G   0% /run/user/1000
/dev/loop3                          64M   64M     0 100% /snap/core20/2182

参考资料

https://linoxide.com/linux-how-to/add-new-disk-centos-7-without-rebooting/

https://www.golinuxcloud.com/extend-resize-primary-partition-non-lvm-linux/