安装 Ubuntu Server 的时候 磁盘分区 选择了 LVM，在安装软件时发现磁盘空间已经无法满足，所以需要利用 LVM 对磁盘进行扩容
查看文件系统磁盘空间的使用情况
root@ubuntu:~# df -h
Filesystem Size Used Avail Use% Mounted on
udev 451M 0 451M 0% /dev
tmpfs 97M 1.3M 96M 2% /run
/dev/mapper/ubuntu--vg-ubuntu--lv 3.9G 3.4G 287M 93% /
tmpfs 482M 0 482M 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 482M 0 482M 0% /sys/fs/cgroup
/dev/loop0 92M 92M 0 100% /snap/core/8689
/dev/loop1 90M 90M 0 100% /snap/core/8268
/dev/sda2 976M 77M 832M 9% /boot
tmpfs 97M 0 97M 0% /run/user/0
可以发现 /dev/mapper/ubuntu--vg-ubuntu--lv 虚拟机根目录空间只有3.9G，使用了93%，不足以再安装MySQL
查看LVM卷组的信息
root@ubuntu:~# vgdisplay
--- 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 <19.00 GiB
PE Size 4.00 MiB
Total PE 4863
Alloc PE / Size 1024 / 4.00 GiB
Free PE / Size 3839 / <15.00 GiB
VG UUID hZPoxm-kSBU-fmKs-2yXD-hHoe-3T7e-PCIFSe
Free PE / Size 3839 / <15.00 GiB，这是还可以扩充的大小
使用命令进行磁盘扩容
lvextend -L 10G /dev/mapper/ubuntu--vg-ubuntu--lv //增大或减小至19G
lvextend -L +10G /dev/mapper/ubuntu--vg-ubuntu--lv //增加10G
lvreduce -L -10G /dev/mapper/ubuntu--vg-ubuntu--lv //减小10G
lvresize -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv //按百分比扩容
resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv //执行调整
具体操作如下
// 按百分比进行磁盘扩容
root@ubuntu:~# lvextend -l +100%FREE /dev/mapper/ubuntu--vg-ubuntu--lv
Size of logical volume ubuntu-vg/ubuntu-lv changed from 4.00 GiB (1024 extents) to <19.00 GiB (4863 extents).
Logical volume ubuntu-vg/ubuntu-lv successfully resized.
// 刷新分区
root@ubuntu:~# resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv
resize2fs 1.44.1 (24-Mar-2018)
Filesystem at /dev/mapper/ubuntu--vg-ubuntu--lv is mounted on /; on-line resizing required
old_desc_blocks = 3, new_desc_blocks = 3
The filesystem on /dev/mapper/ubuntu--vg-ubuntu--lv is now 4979712 (4k) blocks long.
// 查看文件系统磁盘空间的使用情况（发现此时已经扩容到19G）
root@ubuntu:~# df -h
Filesystem Size Used Avail Use% Mounted on
udev 451M 0 451M 0% /dev
tmpfs 97M 1.3M 96M 2% /run
/dev/mapper/ubuntu--vg-ubuntu--lv 19G 3.9G 14G 22% /
tmpfs 482M 0 482M 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 482M 0 482M 0% /sys/fs/cgroup
/dev/loop0 92M 92M 0 100% /snap/core/8689
/dev/loop1 90M 90M 0 100% /snap/core/8268
/dev/sda2 976M 77M 832M 9% /boot
tmpfs 97M 0 97M 0% /run/user/0
// 再次查看LVM卷组的信息（可扩容的空间已经成为0）
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 <19.00 GiB
PE Size 4.00 MiB
Total PE 4863
Alloc PE / Size 4863 / <19.00 GiB
Free PE / Size 0 / 0
VG UUID hZPoxm-kSBU-fmKs-2yXD-hHoe-3T7e-PCIFSe
