By default, RHEL 7 uses the FirewallD service to provide network security. FirewallD must be stopped and disabled when using the iptables service:

# systemctl stop firewalld.service # systemctl disable firewalld.service # systemctl enable iptables.service # systemctl start iptables.service The iptables service is now provided by a separate package called iptables-services:

# yum info iptables-services […]

yum-cron is an optional package starting from Red Hat Enterprise Linux 6, this is a plugin for yum. From man page of yum-cron :

yum-cron is a simple way to call yum commands from cron. It provides configuration to keep repository metadata up to date, and to check for, download, and apply updates. The yum-cron […]

Question: Why CentOS 7 / RHEL 7 have many tmpfs (6 tmpfs filesystem), are these tmpfs mandatory for OS? What are the mount /run/user/1000, /run/user/0, /run/user/45, /sys/fs/cgroup for?

Answer:

If you run df -hP in RHEL 7 system you would find many tmpfs file systems mounted.

# df -hP Filesystem Size Used Avail Use% Mounted […]

Red Hat Enterprise Linux 7 is an major / drastic change to enterprise. To serve / meet today’s business critical application performance RHEL 7 is the best Operating system to use, very light weight and container based. In this article we are going to see RHEL 6 vs RHEL 7 Difference Between Previous and Newer […]

YumDownloader

yum install yum-utils yumdownloader bind-utils [root@lab4 ~]# yum install yum-utils Loaded plugins: fastestmirror Loading mirror speeds from cached hostfile * base: centos.shinjiru.com * extras: centos.netonboard.com * updates: centos.netonboard.com Resolving Dependencies –> Running transaction check —> Package yum-utils.noarch 0:1.1.31-40.el7 will be installed –> Processing Dependency: python-kitchen for package: yum-utils-1.1.31-40.el7.noarch –> Processing Dependency: libxml2-python for package: […]