LVM: Logical Volume Group, It helps to extend the existing filesystem. To extend the filesystem, free space should available in the Volume group. If free space is not available then you need to add new PV(physical volume) and then create a new Volume Group (VG).
Now let’s see how to extend using ‘lvextend’
Step:1 Type ‘lsblk’ to list the file system
Here we want to extend ‘u01-u02’ 40G to 49G with using ‘u01’ VG
Step:2 check VG space available or not
VG ‘u01’ available <11G, we have enough space to extend LV
Step:3 Now run lvextend command to extend ‘u01-u02’ partion
Step:4 check ‘u01-u02’ extended successfully to 49G.
xfs is RHEL 7.x default file system. We can extend xfs file system but can not reduce.