Flash memory in the SAP infrastructure

Currently, hybrid flash solutions still lead the overall market, which according to market researchers from IDC reached a volume of 11.3 billion US dollars in 2014. Fast all-flash systems accounted for USD 1.3 billion of this total.

As acquisition costs continue to fall, all-flash will certainly be used more frequently and thus further increase the performance of the IT infrastructure.

Just a few years ago, attempts were made to increase the latency of data access by using hard disks that run at up to 15,000 rpm. However, these create a high thermal load in the data center and drive up energy costs.

Storage strategy

SAP managers should now examine how they can optimize the current storage strategy by using flash. Many companies will continue to run their core applications such as ERP and Hana on premise despite cloud, for example due to security concerns.

Anyone with a Hana environment installed should take a closer look at flash systems. Flash can help reduce operating costs: A flash PCIe card installed on the server allows more and larger workloads to be processed per CPU core.

In many cases, it is then possible to reduce the number of CPUs in an SAP system. With a per-CPU licensing model, fewer actively used CPU cores also result in lower licensing costs.

Further savings come from reduced space, cooling and power consumption requirements compared to hard disks. In a busy data center, a flash migration therefore offers a great opportunity to reduce IT operating costs.

For a cost-benefit analysis, CIOs should not only look at the acquisition costs of hard disk and flash storage in terms of gigabytes per euro. The true value of flash systems becomes apparent when the transaction performance of both technologies is put in relation to the acquisition costs.

If a flash system can handle more I/O transactions in the same amount of time as a disk-based system, the initial cost can pay for itself very quickly.

Those who want to specifically increase the performance of individual servers with SAP or database systems can use the aforementioned flash memory on PCIe cards for this. The performance leap through PCIe is enormous compared to interfaces like SAS or SATA.

Instead of milliseconds as before, the latency here is in the range of microseconds. The low response times and high transfer rates are achieved because the PCIe card sits directly on the CPU and thus does not have to make a detour via a SAS or SATA controller.

However, this turns PCIe SSDs into local storage, which cannot be easily integrated into existing concepts for high availability and backup.

Which storage solution makes sense for a company has less to do with the data volumes and more to do with the application scenarios - in other words, the workload.

If the data is so-called cold data, such as backup or archive data, somewhat higher response times of the storage systems are still acceptable. However, anyone who processes a very high number of financial transactions with SAP systems or operates a high number of users with virtual desktops in a VDI environment should rely on flash systems.

Flash also offers a speed advantage for backup and development environments. For example, snapshots can be used to restore operational data very quickly. An SAP development environment can also be set up within a few seconds on the basis of a snapshot.

Flash features

For IT managers, it is important to be able to integrate Flash into existing SAP infrastructures as easily as possible. If the speed advantage is negated by increased administration effort, the bottom line is that nothing is gained.

Anyone who brings flash storage into the data center should therefore rely on the experience of a specialist. Flash does pose challenges in terms of sizing, as the performance values are completely different from those of disk-based storage. In principle, flash systems should always be adapted exactly to the individual requirements in the company.

Sometimes performance is the decisive factor, sometimes manageability or orchestration options, and almost always the best possible integration into the existing infrastructure. After all, no IT manager wants to bring a new storage silo into the data center just for SAP applications.

The mixture makes the difference

For those who want to integrate flash technologies as flexibly as possible into the storage infrastructure, NetApp, for example, offers an approach that provides the CIO with a high degree of flexibility.

The combinations of all-flash, hybrid, and pure hard disk-based arrays offered by NetApp work with the Clustered Data Ontap storage operating system. This makes it very easy to operate the systems in a flexibly expandable cluster network.

It is also possible to move data and workloads during operation so that they use different storage systems, up to and including the integration of cloud resources.

NetApp solutions are certified for the SAP Hana TDI model: Systems such as NetApp FAS, for example, integrate with SAP Landscape Virtualization Manager and Hana Studio for backup and recovery.

Conclusion

With memory prices steadily falling, no IT department needs to do without flash. Higher I/Os, reduced latencies and lower power requirements are what make chip-based storage technologies so attractive.

Savings in power consumption, space, and improvements in air conditioning are therefore important factors that pay off for the entire IT infrastructure. In addition to the pure I/O benefits, this can also lead to a need for retrofitting.

The use of all-flash arrays currently remains mostly limited to specialized applications that require the highest performance. Hybrid architectures, on the other hand, support a broader range of uses and can accelerate SAP environments very universally.

This is especially true for uniform workloads that benefit greatly from caching. However, it is likely that more and more hard disks will be replaced by fast flash storage as prices fall.