While RHEL and SLES are technically similar, there are some significant differences between the two companies and their strategies. How will these differing strategies affect you, the IT manager, short term and long term? We take a look at some of the important differences between Novell and Red Hat products and strategies, and draw some conclusions on when and how these differences can affect your data center strategy.
Why is Red Hat the Linux market share leader?
RHEL dominates the Linux distribution market from a revenue and shipment point of view. Red Hat was first to market with a commercial Linux distribution and quickly developed excellent relationships with the largest x86 hardware vendors, Dell and HP.
Anecdotally, RHEL runs on 90% of Dell and HP x86 and x64 servers shipped, and certainly runs on more System x servers than SLES (a big reason for RHEL's dominance).
Red Hat used to have a lead with respect to ISVs, but Novell has actually moved slightly ahead in this race, according to counts of ISV applications online for the two companies.
Red Hat has done a great job selling its open source vision and convincing customers that they can lower costs using open
Mixed source versus open source
What is the big deal around mixed source versus open source? Novell develops and sells both open source and proprietary products. Red Hat develops and sells only open source products.
Most of the important ISV applications (open source and proprietary) are certified to run on both RHEL and SLES -- no real difference there. In addition to Novell developing and selling its own proprietary products, it will work with partners, such as Microsoft, to design and implement proprietary code that will run on SLES and/or Windows. Red Hat will not.
If you like Novell's proprietary products or you are currently running some of them on NetWare and wish to move to Linux, then Novell can provide you with a lot of value. Novell's proprietary products do not generally run on RHEL. Prior to its acquisition of SUSE in 2004, Novell's proprietary products ran primarily on NetWare and Windows. While several of these proprietary products currently run on SLES, not all do -- PlateSpin Migrate runs on Windows, but not SLES. If you don't want to run Novell's proprietary products on Linux, little around mixed source versus open source (with respect to these two companies) that will affect your data center strategy.
Novell and Red Hat: Relationships with Microsoft
Since 2006, Novell and Microsoft have worked closely together to increase the interoperability between SLES and Windows operating systems.
According to Novell and Microsoft, enterprises had been asking for more Linux-Windows interoperability. However, Novell also sought to jumpstart its flat Linux business. Prior to the Novell/Microsoft collaboration agreement in November 2006, Novell had under 20% of the market share (revenue) compared to an almost 80% share for Red Hat for commercial Linux.
The Novell-Microsoft relationship goes beyond technical collaboration and IP protection. There is also strong business collaboration, Microsoft's endorsement of Novell and SUSE Linux Enterprise, and close collaboration on customer support and engineering issues.
Red Hat has not seen the need to develop a Novell-like relationship with Microsoft. For several years, Red Hat denounced Microsoft because of its use of patents to threaten the open source community of developers and because of its failure to open APIs to third-party developers. However, Red Hat and Microsoft have agreed to a narrow virtualization technology relationship with no revenue or patent benefits for either company.
Almost all data centers have Windows servers and over 70% of data centers have Linux servers. Linux-Windows interoperability is a plus for your data center and it can reduce costs and simplify data center operation. Novell has a clear lead on Windows-Linux interoperability.
The questions you should ask when evaluating this issue:
- Is Linux-Windows interoperability an important consideration in your data center?
- Is there anything in your data center that prevent Linux-Windows interoperability, such as political issues, data center location, etc.?
The effects of Linux-Windows interoperability are minimal unless you intend to take advantage of the interoperability in your data center.
Data center management tools
Data center management is one of the primary differences between Novell and Red Hat. Novell strives to be a strong data center management player, and it is attempting to do it with proprietary, agnostic management tools for physical servers (Linux, Unix and Windows) and virtual servers (created by Hyper-V, VMware ESX and Xen). The ZENworks and PlateSpin management tools are the centerpieces of Novell's data center management play.
Red Hat has two primary management tool platforms: Red Hat Network, for managing various aspects of RHEL use, and JBoss Operations Network. Red Hat's focus is on developing open source management tools primarily to manage its own set of products and does not strive to manage an entire data center.
Novell's agnostic data center management tool strategy can theoretically allow you to reduce data center complexity (fewer tools and fewer vendors) and save on management tool costs. But -- and this is a very big BUT -- agnostic tools, designed to manage multiple platforms, generally do not manage all of the important features provided by specific platforms.
Differing virtualization strategies
Novell has based its virtualization software strategy and offerings around Xen and working with its partners, particularly Microsoft and VMware. It touts SLES as the "perfect guest operating system" because of its high performance as a guest on Hyper-V, VMware ESX and Xen.
Red Hat has adopted KVM (kernel virtual machine) as its hypervisor of the future, with a version in RHEL 5.4 to be delivered later this year. Red Hat will fully support Xen through the life of its RHEL 5 family and then focus only on KVM.
If it is important that you choose a single vendor to virtualize your data center workloads today, then it will almost certainly be Microsoft or VMware, since most of the workloads in the data center to virtualize are Windows workloads. Microsoft and VMware dominate this part of the market. My recommendation is that you virtualize Windows workloads with Hyper-V or ESX, and that you virtualize Linux workloads with Novell and Xen or Red Hat and KVM.
What effect does Novell's or Red Hat's virtualization software strategies have on you and your data center strategy? Proponents of Xen claim that the operating system should be separate from the hypervisor. Red Hat claims that new Linux kernel technology will directly advance the capabilities of the KVM hypervisor with new schedulers and improved power management, performance and security.
While Amazon's EC2 cloud is built with Xen, we view Xen support and market share declining long term since Red Hat is focusing on KVM and Citrix is working closely with Microsoft to develop management tools for Hyper-V. Red Hat's roadmap calls for support for migrating Xen virtual servers to KVM, but this support is not imminent. Citrix has a larger market presence than either Novell or Red Hat with respect to Xen. However, depending on Citrix's relationship with Microsoft and Hyper-V, long-term Novell could become the leading supporter of Xen. Novell does not yet fully support KVM, but it will.
If you want to choose an open source hypervisor for virtualizing workloads, you have a choice of KVM or Xen. Today, Xen is established with several enterprise customers. Check both hypervisors out before you deploy either: Examine long-term support for Xen and determine when KVM will be available for enterprise production use.
ABOUT THE AUTHOR: Bill Claybrook is a marketing research analyst with over 30 years of experience in the computer industry with the last 10 years in Linux and Open Source. From 1999 – 2004, Bill was Research Director, Linux and Open Source, at Aberdeen Group in Boston. He resigned his competitive analyst/Linux product marketing position at Novell in June 2009 after spending over four and one half years at the company. He is now President of New River Marketing Research in Concord, MA. He holds a Ph.D. in Computer Science.
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This was first published in August 2009