See explanation below.
Explanation/Reference:
Explanation:
iptables -F
service iptables save
iptables -A INPUT -s 172.25.0.0/16 -j REJECT
service iptables save
service iptables restart

Answer see in the explanation.
Explanation/Reference:
# pvcreate /dev/sda7 /dev/sda8
# vgcreate -s 16M vg1 /dev/sda7 /dev/sda8
# lvcreate -l 50 -n lvm02
# mkfs.ext4 /dev/vg1/lvm02
# blkid /dev/vg1/lv1
# vim /etc/fstab
# mkdir -p /mnt/data
UUID=xxxxxxxx /mnt/data ext4 defaults 0 0
# vim /etc/fstab
# mount -a
# mount
(Verify)

* [root@node1 ~]# yum install chrony
[root@node1 ~]# vim /etc/chrony.conf
pool utility.domain15.example.com iburst
[root@node1 ~]# systemctl enable chronyd
[root@node1 ~]# systemctl restart chronyd
[root@node1 ~]# systemctl status chronyd
[root@node1 ~]# tzselect
Please identify a location so that time zone rules can be set correctly.
Please select a continent, ocean, "coord", or "TZ".
1) Africa
2) Americas
3) Antarctica
4) Asia
11) TZ - I want to specify the time zone using the Posix TZ format.
#? 4
* Please select a country whose clocks agree with yours.
1) Afghanistan 18) Israel 35) Palestine
2) Armenia 19) Japan 36) Philippines
3) Azerbaijan 20) Jordan 37) Qatar
4) Bahrain 21) Kazakhstan 38) Russia
5) Bangladesh 22) Korea (North) 39) Saudi Arabia
#? 5
The following information has been given:
Bangladesh
Therefore TZ='Asia/Dhaka' will be used.
Is the above information OK?
1) Yes
2) No
#? 1
Asia/Dhaka
[root@node1 ~]# chronyc sources -v
^? utility.domain15.example> 0 7 0 - +0ns[ +0ns] +/- 0ns

see explanation below.
Explanation
Addition
df -hT
lvextend -L +100M /dev/vg0/vo
Lvscan
xfs_growfs /home/ //home is the mounted directory of the LVM, this step just need to do in the practice environment, and test EXT4 does not need this step.
resize2fs /dev/vg0/vo// use this command to update in examination.
df -hT
OR
Subtraction
e2fsck -f/dev/vg0/vo
umount /home
resize2fs /dev/vg0/vo // the final required partition capacity is 100M lvreduce -l 100M /dev/vg0/vo mount /dev/vg0/vo/home df -hT

see explanation below.
Explanation
cd /var/www/html
wget
http://instructor.example.com/pub/serverX.html mv serverX.html index.html /etc/init.d/httpd restart chkconfig httpd on