前言：在实际工作中常遇到类似问题，所以特做一次实践，记录下来供大家参考。
环境：centOS 7 虚拟机
配置：1CPU 2G内存 200G硬盘
1.查看分区
[root@test ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/cl-root 50G 1020M 49G 2% /
devtmpfs 901M 0 901M 0% /dev
tmpfs 912M 0 912M 0% /dev/shm
tmpfs 912M 8.6M 904M 1% /run
tmpfs 912M 0 912M 0% /sys/fs/cgroup
/dev/sda1 1014M 139M 876M 14% /boot
/dev/mapper/cl-home 147G 33M 147G 1% /home
tmpfs 183M 0 183M 0% /run/user/0
[root@test ~]# fdisk -l
Disk /dev/sda: 214.7 GB, 214748364800 bytes, 419430400 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000b8796
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2099199 1048576 83 Linux
/dev/sda2 2099200 419430399 208665600 8e Linux LVM
Disk /dev/mapper/cl-root: 53.7 GB, 53687091200 bytes, 104857600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/cl-swap: 2147 MB, 2147483648 bytes, 4194304 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk /dev/mapper/cl-home: 157.8 GB, 157831659520 bytes, 308264960 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
2.终止占用/home进程
a.安装psmisc
[root@test ~]# yum -y install psmisc
b.使用fuser命令
[root@test ~]# fuser -m -v -i -k /home
3.卸载/home
[root@test ~]# umount /home
4.删除/home所在的lv
[root@test ~]# lvremove /dev/mapper/cl-home
Do you really want to remove active logical volume cl/home? [y/n]: y
Logical volume "home" successfully removed
5.扩展/root所在的lv，增加100G
[root@test ~]# lvextend -L +100G /dev/mapper/cl-root
Size of logical volume cl/root changed from 50.00 GiB (12800 extents) to 150.00 GiB (38400 extents).
Logical volume cl/root successfully resized.
6.扩展/root文件系统
[root@test ~]# xfs_growfs /dev/mapper/cl-root
meta-data=/dev/mapper/cl-root isize=512 agcount=4, agsize=3276800 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0 spinodes=0
data = bsize=4096 blocks=13107200, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal bsize=4096 blocks=6400, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
data blocks changed from 13107200 to 39321600
7.重新创建home的lv
[root@test ~]# lvcreate -L 40G -n home cl
Logical volume "home" created.
8.创建文件系统
[root@test ~]# mkfs.xfs /dev/cl/home
meta-data=/dev/cl/home isize=512 agcount=4, agsize=2621440 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=10485760, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=5120, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
9.挂载/home
[root@test ~]# mount /dev/cl/home /home
10.还原/home相关文件以及对应目录权限
[root@test ~]# chmod -R 755 /home
11.结果展现，可以看到/dev/mapper/cl-root已经由50G变为了150G
[root@test ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/cl-root 150G 1.1G 149G 1% /
devtmpfs 901M 0 901M 0% /dev
tmpfs 912M 0 912M 0% /dev/shm
tmpfs 912M 8.6M 904M 1% /run
tmpfs 912M 0 912M 0% /sys/fs/cgroup
/dev/sda1 1014M 139M 876M 14% /boot
tmpfs 183M 0 183M 0% /run/user/0
/dev/mapper/cl-home 40G 33M 40G 1% /home