# cd /root; wget ftp://192.168.0.254/pub/boot.iso
# mkdir -p /media/cdrom
# vim /etc/fstab
/root/boot.iso /media/cdrom iso9660 defaults,loop 0 0
# mount -a
mount [-t vfstype] [-o options] device dir

* [root@node2 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
vdd 252:48 0 5G 0 disk
vde 252:64 0 10G 0 disk
[root@node2 ~]# yum install kmod-kvdo vdo
[root@node2 ~]# systemctl enable --now vdo
[root@node2 ~]# systemctl start vdo
[root@node2 ~]# systemctl status vdo
[root@node2 ~]# vdo create --name=vdo1 --device=/dev/vde --vdoLogicalSize=50G
[root@node2 ~]# vdostats --hu
Device Size Used Available Use% Space saving%
/dev/mapper/vdo1 10.0G 4.0G 6.0G 40% N/A
[root@node2 ~]# mkfs.xfs -K /dev/mapper/vdo1
* [root@node2 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
vde 252:64 0 10G 0 disk
└─vdo1 253:4 0 50G 0 vdo
[root@node2 ~]# mkdir /vbread
[root@node2 ~]# blkid
/dev/mapper/vdo1: UUID="1ec7a341-6051-4aed-8a2c-4d2d61833227" BLOCK_SIZE="4096" TYPE="xfs"
[root@node2 ~]# vim /etc/fstab
UUID=1ec7a341-6051-4aed-8a2c-4d2d61833227 /vbread xfs defaults,x-systemd.requires=vdo.service 0 0
[root@node2 ~]# mount /dev/mapper/vdo1 /vbread/
[root@node2 ~]# df -hT
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/vdo1 xfs 50G 390M 50G 1% /vbread

see explanation below.
Explanation
groupadd admin
useradd -G admin mary
useradd -G admin alice
useradd -s /sbin/nologin bobby
echo "password" | passwd --stdin mary
echo "password" | passwd --stdin alice
echo "password" | passwd --stdin bobby

see explanation below.
Explanation
* echo "1" >/proc/sys/net/ipv4/ip_forward
* vi /etc/sysctl.conf
net.ipv4.ip_forward = 1
If you want to use the Linux System as a Router to make communication between different networks, you need enable the IP forwarding. To enable on running session just set value 1 to
/proc/sys/net/ipv4/ip_forward. As well as automatically turn on the IP forwarding features on next boot set on
/etc/sysctl.conf file.

Answer see in the explanation.
Explanation/Reference:
# fdisk /dev/sda
p
(check Partition table)
n
(create new partition: press e to create extended partition, press p to create the main partition, and the extended partition is further divided into logical partitions) Enter
+2G
t
l
W
partx -a /dev/sda
partprobe
mkswap /dev/sda8
Copy UUID
swapon -a
vim /etc/fstab
UUID=XXXXX swap swap defaults 0 0
(swapon -s)