Mainframe data centers have many platform options for running Linux. The challenge is deciding where: x86 servers and blades, IBM Power Systems, HP Itanium, Oracle/Sun, IBM’s System z or zEnterprise.
Here is what IBM has to say about the various options: System z / zEnterprise, Power/System p/System i, and System x blades and rack mount servers. And now with the zBX there is yet another option, Linux blades on the zBX. But this doesn’t answer the real question: where should your organization run Linux?
If you have only one platform the answer is simple. Linux has been widely ported. You can probably run it on whatever you already have.
Most organizations today, especially enterprise data centers, have multiple platforms running Windows, Linux, UNIX, AIX, Solaris, and more. And they run these on different hardware platforms from IBM, HP, Oracle/Sun, Dell, and others. Now the decision of where to run Linux gets complicated. The classic consultant/analyst response: it depends.
Again, IBM’s response is to lead the organization through a Fit for Purpose exercise. Here is how IBM discusses the exercise in regard to cloud computing. DancingDinosaur addressed Fit for Purpose here last year.
The Fit for Purpose exercise, however, can be reduced to four basic choices:
- Where does the data that your Linux applications will use most reside—in general you will get the best end-to-end performance the closer the data is to the applications. So, if your Linux applications need to use DB2 data residing on the mainframe, you probably want the run Linux on the System z or a zBX blade.
- Since cost is always an issue look at the price/performance numbers—in this case you have to look at all the costs, paying particular attention to cost in terms of performance delivered. Running Linux on a cheap, underpowered x86 box may cost less but not deliver the performance you want.
- Available skills—here you need to look at where the Linux and platform skills available to you fall and opt for the platform where you have the most skills availability. Of course, a relatively modest investment in training can pay big dividends in this area.
- IT culture—to avoid resistance even if the data proximity or price/performance considerations fall one way, many might opt for the platform favored by the dominant IT culture.
Further complicating the decision is the lack of good data available on both the cost and the performance of Linux on the zBX or its Linux blades. Plus there are other variables to consider, such as whether you run Linux on an IFL on the z with or without z/VM. Similarly, you can run Linux on an x-platform with or without VMware or some other hypervisor. These choices will impact price, performance, and skills.
Although the answer to the question of where to run Linux may not be as simple as many would like, DancingDinosaur believes as a general principle it is always better to have choices.