IT Management

Enterprises that trusted in the mainframe myths and moved their corporate databases to distributed platforms are spending 100 percent more than necessary on database servers, creating data integrity issues and increasing the data risk exposure by constraining the ever-shrinking backup window. By moving databases from shared-nothing distributed data servers to the shared storage environment of IBM zEnterprise systems and putting the applications on Integrated Facility for Linux (IFL) processors and an IBM zEnterprise BladeCenter Extension (zBX), IT executives can reduce their ecosystem costs by more than 50 percent per year.

At Robert Frances Group (RFG), we completed a Total Cost of Ownership (TCO) analysis of the traditional distributed Linux and Microsoft Windows environment vs. a zEnterprise with zBX environment that consolidates the databases on the mainframe and found the distributed environment to be twice as expensive. Our study used the standard three-year zEnterprise leasing and refresh strategy and traditional five-year purchase plan for the distributed x86 scale-out scenario. IT executives should evaluate the shared zEnterprise database server alternative to lower costs, improve productivity and reduce data risk. Additionally, IT executives should work with IBM or a third-party lessor to structure a package that best meets current and future business, financial and IT objectives.

We had several ideas and hypotheses in mind before conducting our analysis. Specifically:

• The scale-out distributed server model using shared-nothing databases is costly and inefficient, creates data integrity and operational exposures, and fails as a best practice. A switch to using the mainframe as a database server eliminates the need for database duplication and synchronization since the mainframe uses a shared-everything architecture. While the acquisition cost of the zEnterprise and zBX servers collectively runs more than distributed x86-based servers, this is more than compensated for by the drastic reduction in database arrays and their associated costs. IT executives should assess the platform options holistically rather than piecemeal to identify the optimal solution.
• A zEnterprise environment can place Linux applications on IFLs and Windows applications on a zBX. Using this tightly knit, workload-optimized solution reduces the number of processors required, improves application and system management, and uses a high-speed interconnect so performance isn’t diminished when shifting to a shared-everything database engine. A zEnterprise solution enables enterprises to improve automation, control, security and visibility to their applications and databases without degrading performance. IT executives should determine which applications and databases should move to a zEnterprise environment and perform a TCO analysis to gain executive buy-in for the shift.
• Several non-financial gains accrue when moving to a shared-everything storage environment and these should also be factored into the decision-making process. Having a single copy of data means there’s only one version of the truth, all outputs and reports will be consistent and keeping things in synch won’t require manual manipulation, which is error-prone. Most enterprises today spend between 25 and 45 percent of their time synchronizing the many database copies. The associated time consumption used for duplication also creates a backup exposure; some backups don’t occur when administrators are pressed for time. Business and IT executives should consider these data integrity and risk exposures.
• Most IT executives have blindly accepted as fact the theorem that distributed processing is the least expensive solution. This hypothesis has gained ground because of a focus on a Total Cost of Acquisition (TCA) perspective. If the only valid cost analysis is the TCA of servers, then this might hold water. However, when the entire ecosystem is analyzed—including administrator costs, application and middleware software license and maintenance fees, cabling, networking, servers, storage, floor space and power and cooling—this theory falls apart.
• When the zEnterprise is used as a database server and IFLs and zBX are fully leveraged—and the analysis occurs holistically—a different picture emerges. The zEnterprise environment costs more than 50 percent less than that of a distributed x86 ecosystem, mostly due to the savings on storage, administrator, warranty and software costs.
• The mainframe architecture supports shared-everything storage while all distributed operating system platforms use a shared-nothing architecture. The mainframe architecture is unique in that multiple workloads share processors, cache, memory, I/O and storage. Moreover, zEnterprise systems provide data, IT and storage management practices and processes that facilitate and simplify the centralized, shared environment and enable application and database multitenancy. This means mainframe applications can share a single instance of a database, such as customer data, while distributed systems force the creation of a copy for each application’s use.
• Often, companies have between seven and 50 copies of the same database in use, so every terabyte of data stored is expanded by requirements for archiving, backup, mirroring, snapshots, test systems and more (see Figure 1). This data store expansion is then duplicated by the number of copies the distributed systems require. Thus, 1 TB of data in a distributed environment could grow to in excess of 100 TBs—more than 10 times the amount needed when databases are shared using a zEnterprise. There are software clustering solutions to get around this distributed duplication phenomenon and some of the storage sprawls, but they’re partial fixes and only address certain data sets.
• Mainframe storage capacity requirements are a fraction of what’s required for distributed systems. Annual acquisition costs for additional storage on a mainframe will be far less than that for distributed storage solutions. The capital expenditure (CAPEX) savings from the differential in storage costs when mainframes are used as a database engine far exceed the added expense of the mainframe hardware. The mainframe’s smaller storage footprint will reduce the operational expenditures (OPEX) and lower the TCO.

The Methodology

We hypothesized that a large Small to Midsized Business (SMB) with revenues between $750 million and $1 billion might operate a more economical data center environment if it used the new zEnterprise architecture and the mainframe as a database server. Most SMBs run their applications on Windows and/or Linux on x86-architected servers that don’t offer the advantages of a scale-up architecture. Let’s assume AB Co. (ABCo) runs 500 applications with 75 percent of them (375) executing on top of the Windows operating system. The remaining applications (125) run on Red Hat's Enterprise Linux. Additionally, 10 percent are CPU-intensive and require their own blade servers. All other applications operate under either VMware or KVM, depending on whether they’re Windows or Linux applications, respectively. The application workload growth rate is at 20 percent per year.

We also assumed a Storwize V7000 Unified Storage System houses the databases for the mainframe and distributed environments. To keep the analysis from becoming too complex, only two sizes of databases are used (1 and 2 TBs) and each application accesses 10 databases, half of each size. The storage growth rate is 25 percent. There are a total of 70 unique databases, half of each size. For the purposes of the study, only the production servers and storage are included; excluded are the archive, backup and snapshot copies of data. Because a Storwize storage solution is used, we assume a 60 percent utilization is achieved in all environments.

We further assumed that 126 TB of storage is required to handle storage needs for the first 12 months of operation. This includes an additional 20 percent for duplicate databases for the mission-critical applications. On the x86 side, since this is a shared-nothing framework, a minimum set of seven copies of databases would be needed. This results in the total initial storage capacity of 770 TB being required to support the storage needs of the first year’s operation. Finally, note that DB2 10 for z/OS is the database software used to access all databases.

The x86 server scenario uses all IBM 16-core HX5 blade servers for application and database processing. The zEnterprise uses the Central Processing (CP) environment to handle all the database interactions, exploits IFLs for all of the Linux workloads and the zBX for the Windows workloads. In this way, each workload is allocated to the server platform best-suited to perform the task. We further assumed the x86 servers were purchased and kept in operation throughout the five-year analysis period while the zEnterprise boxes were leased and refreshed at the end of three years.

The Distributed Approach

We assumed the distributed environment used 24 16-core HX5 blade servers to handle the 500 Linux and Windows applications. Since these environments require shared-nothing storage, the Storwize solution ends up requiring 126 enclosures and 1,285 raw TB of storage. All the hardware was purchased with the financing of the purchase price spread out over the five-year period. To meet the additional capacity demands year-over-year, new servers or storage arrays were purchased using the same methodology.

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