setting admin pwd
$ passwd
and type the pwd

$exit
to exit from sub-shell bash

$exit
to exit from arch-chroot

$umount /mnt/{home,boot}

$reboot

and then choose "Boot existing OS"

Note: by default there is no netwok i-faces up
need to do the same stuff for network

$cd /etc/network.d
$cp examples/ethernet-dhcp .

$ip link
  to check

edit INTERFACE='enp0s3'

$ netcfg ethernet-dhcp