报错write error file system full原因及解决方案

在虚拟机上配置文件保存时报write error (file system full)
原因：磁盘满了
查看磁盘 df -h
发现：/dev/mapper/ubuntu–vg-ubuntu–lv100%（此处是扩容后的结果）

Filesystem                         Size  Used Avail Use% Mounted on
udev                               1.9G     0  1.9G   0% /dev
tmpfs                              393M  1.8M  391M   1% /run
/dev/mapper/ubuntu--vg-ubuntu--lv   17G   13G  3.0G  81% /
tmpfs                              2.0G     0  2.0G   0% /dev/shm
tmpfs                              5.0M  4.0K  5.0M   1% /run/lock
tmpfs                              2.0G     0  2.0G   0% /sys/fs/cgroup
/dev/nvme0n1p2                     2.0G  219M  1.6G  12% /boot
/dev/loop2                          49M   49M     0 100% /snap/core18/1708
/dev/nvme0n1p1                     1.1G  5.1M  1.1G   1% /boot/efi
tmpfs                              393M   24K  393M   1% /run/user/128
tmpfs                              393M   28K  393M   1% /run/user/1000
/dev/sr0                           874M  874M     0 100% /media/zhangqin/Ubuntu-Server 20.04 LTS arm64
/dev/loop4                          60M   60M     0 100% /snap/core20/1627
/dev/loop5                          50M   50M     0 100% /snap/core18/2570
/dev/loop6                         108M  108M     0 100% /snap/lxd/23543
/dev/loop0                          42M   42M     0 100% /snap/snapd/17032
/dev/loop7                          42M   42M     0 100% /snap/snapd/17339
/dev/loop8                         132M  132M     0 100% /snap/lxd/23687

执行命令：lsblk 查找未挂载点

扩展3G：

lvextend -L +3G /dev/mapper/ubuntu--vg-ubuntu--lv

扩展后执行命令：

resize2fs /dev/mapper/ubuntu--vg-ubuntu--lv

最后执行 df -h查看就可以了