0.查看磁盘分区情况
blkid -o list fdisk -l cfdisk lsblk
1.查看分区
df -h
2.备份home分区文件
tar cvf /tmp/home.tar/home
3.卸载/home，如果无法卸载，先终止使用/home文件系统的进程
fuser -km /home/ umount /home
4.删除/home所在的lv
lvremove/dev/mapper/centos-home
5.扩展/root所在的lv，增加800G
lvextend -L +800G/dev/mapper/centos-root
6.扩展/root文件系统
xfs_growfs/dev/mapper/centos-root
7.重新创建home lv
lvcreate -L 73G -n/dev/mapper/centos-home
8. 创建文件系统
mkfs.xfs /dev/mapper/centos-home
9.挂载home
mount/dev/mapper/centos-home
10.home文件恢复
tar xvf /tmp/home.tar -C/home/ cd /home/home/ mv * ../
参考：
https://jingyan.baidu.com/article/7e4409532db33f6ec1e2ef66.html
https://zhuanlan.zhihu.com/p/586839216
https://blog.csdn.net/Cecidit_824/article/details/131245922
https://blog.csdn.net/e_wsq/article/details/79531493