I never realized in depth the difference between a Linux subscription and a license. Linux is open source, so the software itself is for free. No license to use it is required. But when you buy a Linux support subscription, you are legally entitled to download the ISO images of the binary distribution, download bug fixes, raise bugs and get support from a distributor. Hmm… that sounds pretty much the same as a license. But… with a subscription you can switch to another, cheaper support provider for the same product. It’s quite the same as switching your energy-supplier to another company.
So why not change the subscription of Red Hat Linux to Oracle – without changing a bit of RHEL and no downtime involved. And save money, because the subscription of Oracle looks cheaper (!). The distribution of Oracle Linux is binary compatible with Red Hat Linux, and will provide the same updates and errata.
Is it really that simple to save money? Or are there important pitfalls? Is it worth investigating for Red Hat based datacenters? And … is a Red Hat Linux, maintained by Oracle still a Red Hat Linux, or do you call it Oracle Linux with RHEL compatible kernel? Lots of questions. Let’s take a closer look.
Technical change
A Red Hat Linux distribution gets its updates and errata from a so-called YUM-repository, and so does Oracle Linux. The command-lines are basically the same. The only thing you have to do is move the pointer to the Oracle YUM-repository. Without any change of the O.S., downtime or what so ever.
With a few commands / actions you switch to the payed subscription of Oracle, and connect to the ULN (Unbreakable Linux Network)-repository. :
1. Buy a subscription for Oracle Linux, choose your support level.
2. Get a ULN account this is mandatory for this type of subscription.
3. Switch over to another YUM repository and register your system. Typically you register only once. You need to migrate only one server to ULN and for rest of the servers either create a local ULN mirror (below: ‘local YUM server’). What kind of descriptions you use at your local servers that use the local YUM server is your own choice. It can even be a free subscription. Is it allowed and advisable to have a mixed subscription in your company? I’ll come to that later on in a separate chapter.
Optionally: you may use Spacewalk server, an open source Linux Management System which can be used for inventory, install/update, provisioning and deploying software on your system.
Here an example of how to change to the Oracle Linux subscription (Linux 6, http://linux.oracle.com/switch/ ). First step is to install the packages, second step is to register you system.
Step 1: Switch over by installing rpm.
# wget http://linux-update.oracle.com/rpms/uln_register.tgz # wget http://linux-update.oracle.com/rpms/uln_register-gnome.tgz
# tar -xzf uln_register.tgz
# tar -xzf uln_register-gnome.tgz (only if rhn-setup-gnome is already installed)
# cd uln_migrate
# rpm -Uvh *.rpm
Note: rhn-setup-gnome contains a GTK+ graphical interface for configuring and
registering a system with a Red Hat Satellite or Spacewalk server.
step 2: Register your system to ULN by running following command as root
# uln_register
Run following command if libreport-plugin-rhtsupport package is installed:
# yum shell
> remove libreport-plugin-rhtsupport
> update libreport abrt
> run
> quit
A nice video from Steen Schmidt (Oracle Denmark) shows the change: https://www.youtube.com/watch?v=ZIXaMihrwuc
Prices
An important part of making decisions about migrating may be the price, and the subscription of Oracle Linux looks indeed cheaper than Red Hat Linux. Oracle even has a calculator to emphasize this. But, as with every comparison between rivalry products, you must take into account the assumptions the made here (button ‘Assumptions’ at the calculator page at the top).
The most striking assumption here is the comparison between Oracle Basic Support with Red Hat Premium Support. Oracle claims that the free version of Oracle Linux is roughly equivalent to the payed self-support subscription Red Hat offers.Furthermore, the basic Oracle linux subscription is equivalent to Red Hat Premier Support.
So… the Premier support of Oracle can’t be compared to a similar product of Red Hat, following this train of thought 
. Probably while the most important feature of Premier support, Ksplice, has no equivalent yet at RHEL.
You can argue about prices and assumptions, but nothing beats a free subscription when the quality of that subscription is suitable for (part of) your business. For example your development and test-teams.
Wim Coekaerts has a nice blog explaining the price structure of Oracle Linux: https://blogs.oracle.com/wim/entry/oracle_linux_and_oracle_vm .
Some statements from that blog:
– “Oracle will provide its Red Hat compatible Linux binaries, updates and errata for free.”
– “You can freely download Oracle Linux, install it on any number of servers and use it for any reason, without support, without right to use of these extra features like Oracle Clusterware or ksplice, without indemnification. However, you do have full access to all errata as well. “
Consequences
I won’t give a statement about the quality of both the Linux distributions. There’s an excellent blogpost about Oracle Linux by Tim Hall and Oracle has its own FAQ’s about Oracle Linux. It will give a good idea of its position in the Linux community and the main differences between RHEL and Oracle Linux.
What will change when you switched to an Oracle subscription?
– You could ask the following question: when someone has migrated the RHEL-subscription to Oracle ULN, will the o.s. still be called RHEL, or has it become Oracle Linux with RedHat compatible kernel? Well, the system will still be a RHEL, and over time the package/patches will exchange RHEL with Oracle branded package/patches, but the kernel will still be the RHEL Kernel until a major shift eg. 6 to 7. Only then it will be the 100% binary RHEL Kernel. You may also decide then or in the near future to switch over to the UEL kernel.
– When using provisioning software like Puppet, there’s no problem at all, this supports Oracle Linux.
– Many customers of Red Hat are using Satellite as management system for patching, provisioning and monitoring, so this could be a reason not to switch. The counterpart of Oracle, Spacewalk (see statement oracle below) and Oracle Enterprise Manager are more than able to replace this functionality. Nice to know: lifecycle-management is free for o.s.-level !
Spacewalk is the upstream community project from which the Red Hat Satellite product is derived. The Oracle statement on Spacewalk:
– For Oracle and Spacewalk, there is no additional education involved for system administrators, as RH Satellite is derived from the Spacewalk project, also used by Red Hat. The main differences are described at the RedHat site.
– Customers want all their environments (development, test, acceptance, production etc) completely equal for continuous delivery reasons for example. However, this is not the case when only registering the production-environment to ULN. Or is it? When the environments are set up as just described in the technical change chapter, every system uses the same local YUM-repository. And as long as you patch the systems from this local YUM-server (synced with ULN) there’s no problem. But note that Dtrace or Ksplice can only be used on systems for which premier support has been bought.
Will Oracle check on you for any incompliance when using Dtrace or Ksplice for example on systems with no subscription? Officially, it’s NOT part of the job description of LMS (License Management Service), mainly because it’s not considered a license. But why should you be incompliant, the rules are fairly simple, prices are fair.
Brings us the question: why is Oracle a bit indifferent for the possibly incompliancy for Oracle Linux.
Why
The reason why Oracle provides such a cheap subscription and doesn’t care much about the way of using Oracle Linux is quite obvious: to bug the competitors, and bind customers to Oracle even more. I think there’s no more behind it.
So what Oracle is providing here is a free enterprise distribution with the same SLA for updates that paying customers get from Red Hat. There’s no official Oracle guarantee on the updates for the free edition. However, as long as Oracle provides the updates and errata to paying customers within the bounds of an SLA, the same updates can be expected to become available at the same time for the non-paying users.
Disregard the possible emotions of getting support of Red Hat : it may be a wise business decision to at least investigate the possibility to migrate the Red Hat subscription to Oracle’s ULN.
Resources:
– ULN-account: http://linux.oracle.com/register
– EM12c Base Enterprise Manager Functionality
” The release of Oracle Enterprise Manager Cloud Control 12c makes several licensing changes. Some features that were part of licensed packs are now included in the base functionality.”
http://docs.oracle.com/cd/E24628_01/doc.121/e24474/ch10_base_functionality.htm#OEMLI333
– Spacewalk 2.0 provided to manage Oracle Linux systems : https://blogs.oracle.com/wim/entry/spacewalk_2_0_provided_to
– Linux Cost Calculator: http://www.oracle.com/us/media/calculator/linuxtco/index.html
Migrating to Oracle Linux – an Economic Value Analysis: http://www.oracle.com/us/technologies/linux/migrating-to-oracle-linux-evaluator-2717423.pdf
– Switch in youtube: https://www.youtube.com/watch?v=ZIXaMihrwuc
– Difference between Red Hat Satellite / Spacewalk: http://spacewalk.redhat.com/faq.html#compare
