UNIX / Linux command-line interface.

Upgrading Red Hat Enterprise Linux / CentOS

RHEL/CentOS 5–6–7 Migration:
Network Services

The details of how to control network services hasn't changed, although the mix of services has. Almost nothing runs through xinetd any more, as systemd has taken its place. About all that's left running through xinetd are the dangerous and unneeded chargen, discard, and echo services, plus the time and daytime services which are simply unneeded since the invention of NTP. Samba has been greatly improved with the release of its version 4, and the old web-based administration tool has been dropped due to many security holes and very little maintenance. Services like Apache and BIND have been through several upgrades, but most of us see that as bug fixes only.

Previous: Networking

The previous page explained the many changes in networking, including changes in network interface names and in the networking commands. It also described how Red Hat has been pushing their firewall daemon for access control.

9 — Networking: Network Services, and
10 — Print and File Service

For RHEL 6, see the earlier discussion of the media split into DVD1 and DVD2. If you want samba-swat, lpd-cups, and several other network servers, you will need to get the packages from DVD2 in RHEL 6.

Better yet, add the CentOS.org YUM respository and install things from there.

RHEL 7 includes an update to Samba 4, meaning that your Linux server can function as a full Active Directory server.

That also means that you can no longer use SWAT or the browser-based Samba Web Admin Tool. It was removed at Samba version 4.1 due to security concerns.

cvs and tftp are the only xinetd services left in RHEL 7, everything else runs as a standalone network service. (Except for some truly antiquated services like chargen and discard that included in the xinetd package) Verify this with:

# cd /path/to/package/files
# for P in *
> do
>   echo $P $( rpm -qlp $P 2> /dev/null | grep '/etc/xinetd.d' ) | grep '/etc/xinetd.d'
> done 
Next: Kernel, Clusters

The kernel itself continues to evolve rapidly. Added features, improved performance, and bug fixes. But the way you configure a kernel hasn't changed much.

Clusters, on the other hand, work completely differently in RHEL/CentOS 7.

Kernel & Clusters