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Should you deploy Linux on the mainframe?
There are plenty of positives and negatives that make it clear that a Linux mainframe isn't right for all IT shops. Two experts go head to head on how to decide what's right for your data center: Linux workloads on a mainframe or running them in a distributed server environment.
Pro: Linux on a mainframe
Get reliability, availability, security and performance by putting workloads on the mainframe.
"Simply put, if you are looking to run a large number of virtual machines in an environment with tons of memory, in an environment that is extremely energy efficient and in an environment that is highly manageable -- [IBM] System z should be evaluated," said Joe Clabby, president of Clabby Analytics.
Mainframes guarantee safety; with an Evaluation Assurance Level of 5+, mainframes have the highest security rating. The newest version of the Linux kernel can run mission-critical applications without the risk of breach or disruption. Securing centralized mainframes is easier than securing hundreds of distributed Linux servers; administrators have to attend to each network interface individually on each box and lock down all access points.
The mainframe has higher resource use rates than distributed server environments. Linux processors on the mainframe handle workloads instantly and efficiently. Running Linux workloads on a System z mainframe is cheaper than on a distributed server because software license fees are coupled with processor cores.
Virtualization and provisioning techniques also increase mainframe use rates. Keep the mainframe busy and it will provide the highest return on investment.
Against: Linux mainframe might not be for you
If you don't want a Linux mainframe, don't worry. You aren't alone, according to Robert Crawford, a systems programmer and SearchDataCenter contributor. A Linux mainframe isn't right for everyone.
"We couldn’t make the economics work due to sweetheart hardware and Linux vendor agreements, along with our distributed environment already being aggressively virtualized. Finally, we couldn’t make large pieces of our infrastructure tooling work on zLinux," said Crawford, which is why he didn't deploy Linux on z.
IBM offers the Integrated Facility for Linux (IFL) engines, making the Linux mainframe a reality. But how valuable is this processor?
Consolidating many workloads from underused servers onto fewer mainframe IFLs makes for a successful migration to z/Linux. But hypervisors are increasingly consolidating server workloads -- even mission-critical ones. This makes migrating to IFLs less attractive because the economics of the Linux mainframe conversion change significantly.
Then there are concerns with performance and price. Not all Linux operating systems work similarly on mainframe processors, and enterprise editions differ in price as well: Linux distribution providers price the mainframe software uniquely.
The hardware for the mainframe and other server infrastructures also require different skill sets and expertise. Commodity hardware is less expensive than mainframe processors.
Eliminating the mainframe could help eradicate office politics. Talk about moving workloads between platforms and an IT war will break out. An impartial study on a workload that includes all parties is the best approach. How do you decide which platform is right for the task? Put the workload on z/Linux and on a Linux server cluster, and see how it runs.
Disclaimer: Every workload is different, as is every business. Use these counter arguments as a starting point to make best decision for your IT organization.
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