hard drive - Root volume /dev/mapper/centos-root full

On one of my host, i have /dev/mapper/centos-root reporting almost full (99%), here is output of df -h.

==

[root@LA3QSSD02-20217 /]# df -h
Filesystem                                       Size  Used Avail Use% Mounted on

/dev/mapper/centos-root                           50G   50G  540M  99% /
devtmpfs                                          63G     0   63G   0% /dev
tmpfs                                             63G   64K   63G   1% /dev/shm
tmpfs                                             63G   18M   63G   1% /run
tmpfs                                             63G     0   63G   0% /sys/fs/cgroup
/dev/sdy1                                        494M  210M  285M  43% /boot
/dev/mapper/centos-home                          411G   33M  411G   1% /home
/dev/mapper/datastore-datastore                   11T  548G  9.1T   6% /datastore 
/dev/mapper/data-sdx                             734G   73M  734G   1% /data-sdx 
/dev/mapper/data-sdf                             734G   73M  734G   1% /data-sdf

/dev/mapper/data0                                734G   80M  734G   1% /data0 
/dev/mapper/data-sdd                             734G   73M  734G   1% /data-sdd 
/dev/mapper/data-sdt                             734G   73M  734G   1% /data-sdt 
/dev/mapper/data-sdg                             734G   73M  734G   1% /data-sdg 
/dev/mapper/data-sdu                             734G   73M  734G   1% /data-sdu 
/dev/mapper/data-sdb                             734G   73M  734G   1% /data-sdb
10.253.48.21:/vol/eq1ag4rdtest01/kvm_ostemplates 3.0T  1.8T  1.3T  58% /vol/eq1ag4rdtest01/kvm_ostemplates
tmpfs                                             13G     0   13G   0% /run/user/0

==

Im unable to find out what is causing / to report full, here is some more details.

++++

0       bin
229M    boot

5.5M    data0
0       data-sdb
0       data-sdc
0       data-sdd
0       data-sde
0       data-sdf
0       data-sdg
0       data-sdh
0       data-sdi
0       data-sdj

0       data-sdk
0       data-sdl
0       data-sdm
0       data-sdn
0       data-sdo
0       data-sdp
0       data-sdq
0       data-sdr
0       data-sds
0       data-sdt

0       data-sdu
0       data-sdv
0       data-sdw
0       data-sdx
698G    datastore
152K    dev
24M     etc
320K    home
0       lib
0       lib64

0       media
0       mnt
171M    opt
0       proc
160M    root
115M    run
0       sbin
20K     sharedstore
0       srv
0       sys

40K     tmp
2.6G    usr
1.8G    var
1.7T    vol

+++++

Please help me in find out what is consuming space on / and how to free it.

Thanks

Regards
Aun