ubuntu使用lvextend扩容LVM磁盘（磁盘不足）

1.查看磁盘占用

root@wwyt-prod06-hlsh:~# df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               3.9G     0  3.9G   0% /dev
tmpfs                              793M   50M  744M   7% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   29G   29G     0 100% /
tmpfs                              3.9G     0  3.9G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              3.9G     0  3.9G   0% /sys/fs/cgroup
/dev/sda2                          976M  108M  802M  12% /boot
/dev/loop0                          72M   72M     0 100% /snap/lxd/16099
/dev/loop1                          45M   45M     0 100% /snap/snapd/15534
/dev/loop2                          68M   68M     0 100% /snap/lxd/22753
/dev/loop3                          44M   44M     0 100% /snap/snapd/15177
/dev/loop4                          62M   62M     0 100% /snap/core20/1405
/dev/loop5                          55M   55M     0 100% /snap/core18/1880
/dev/loop6                          62M   62M     0 100% /snap/core20/1376
/dev/loop7                          56M   56M     0 100% /snap/core18/2344

发现磁盘已占满，需要扩容；

2.查看系统卷组：

root@wwyt-prod06-hlsh:~# 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               <59.00 GiB
  PE Size               4.00 MiB
  Total PE              15103
  Alloc PE / Size       7552 / 29.50 GiB
  Free  PE / Size       7551 / <29.50 GiB
  VG UUID               P0V2bc-ClZT-rZXH-P8RU-fT4R-Jrhx-176qNw

其中，Free PE / Size 7551 / <29.50 GiB 是剩余还可使用的空间，

3.执行扩容指令（示例）：

root@wwyt-prod06-hlsh:~# lvextend -L 50G /dev/mapper/ubuntu--vg-ubuntu--lv     //增大至50G

  Size of logical volume ubuntu-vg/ubuntu-lv changed from 49.50 GiB (12672 extents) to 50.00 GiB (12800 extents).
  Logical volume ubuntu-vg/ubuntu-lv successfully resized.

4.重新计算磁盘大小

root@wwyt-prod06-hlsh:~# 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 = 4, new_desc_blocks = 7
The filesystem on /dev/mapper/ubuntu--vg-ubuntu--lv is now 13107200 (4k) blocks long.

5.再次查看磁盘情况

root@wwyt-prod06-hlsh:~# df -h
Filesystem                         Size  Used Avail Use% Mounted on
udev                               3.9G     0  3.9G   0% /dev
tmpfs                              793M  1.6M  792M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   50G   29G   19G  61% /
tmpfs                              3.9G     0  3.9G   0% /dev/shm
tmpfs                              5.0M     0  5.0M   0% /run/lock
tmpfs                              3.9G     0  3.9G   0% /sys/fs/cgroup
/dev/sda2                          976M  108M  802M  12% /boot
/dev/loop2                          56M   56M     0 100% /snap/core18/2344
/dev/loop3                          72M   72M     0 100% /snap/lxd/16099
/dev/loop1                          62M   62M     0 100% /snap/core20/1405
/dev/loop0                          62M   62M     0 100% /snap/core20/1376
/dev/loop4                          55M   55M     0 100% /snap/core18/1880
/dev/loop5                          68M   68M     0 100% /snap/lxd/22753
/dev/loop6                          45M   45M     0 100% /snap/snapd/15534
/dev/loop7                          44M   44M     0 100% /snap/snapd/15177
tmpfs                              793M     0  793M   0% /run/user/0

root@wwyt-prod06-hlsh:~# 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               <59.00 GiB
  PE Size               4.00 MiB
  Total PE              15103
  Alloc PE / Size       12800 / 50.00 GiB
  Free  PE / Size       2303 / <9.00 GiB
  VG UUID               P0V2bc-ClZT-rZXH-P8RU-fT4R-Jrhx-176qNw