1、LV缩小

命令格式：lvreduce -L -<容量>(M,G）  LV<名称>

例：

 [root@localhost ~]# lvreduce -L -50M /dev/VG0/LV0
 Rounding size to boundary between physical extents: 48.00 MiB.
 WARNING: Reducing active and open logical volume to 444.00 MiB.
 THIS MAY DESTROY YOUR DATA (filesystem etc.)
 Do you really want to reduce VG0/LV0? [y/n]: y
 Size of logical volume VG0/LV0 changed from 492.00 MiB (123 extents) to 444.00 MiB (111 extents).
 Logical volume VG0/LV0 successfully resized.
 [root@localhost ~]# lvs
 LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
 LV0 VG0 -wi-ao---- 444.00m

注：Linux7只能对LV动态扩容，因XFS文件系统不支持缩减

2、VG的缩减（前提pv没有被使用）

命令格式：vgreduce vg<名称>  pv<名称>

例：

 [root@localhost ~]# vgreduce VG0 /dev/sdb3
 Removed "/dev/sdb3" from volume group "VG0"
 [root@localhost ~]# pvs
 PV VG Fmt Attr PSize PFree
 /dev/sdb1 VG0 lvm2 a-- 196.00m 48.00m
 /dev/sdb2 VG0 lvm2 a-- 296.00m 0
 /dev/sdb3 lvm2 --- 500.00m 500.00m