Examining what products the leading all-flash array vendors offer

The key to selecting an all-flash array vendor

You might be tempted to start with the budget and look for the best performance or highest capacity available for a given price. This can be a difficult approach. All-flash array vendors and their partners seldom make pricing available upfront because they don't want you to comparison shop. Even then, the costs of the maintenance and support contracts, discounts and the time left in the quarter can all affect pricing.

Some vendors will not quote you a price until after you have had a couple of presale discussions with their marketing team, a systems engineer and a sales rep. Others have a relatively simple pricing structure with an all-inclusive software package and a somewhat small number of models. If one of those packages fits your needs, it may be a bargain, or you may end up spending more than you would if you had purchased an a la carte configuration from another vendor.

So where do you begin? The best place to start is with a functional specification. This means measuring your apps and finding bottlenecks, which may or may not be solved with faster storage. For instance, if you have several virtual desktop infrastructure (VDI) clients doing computer-aided design, virtual reality development or video, faster storage may not be the entire answer. You might need to invest in graphics coprocessors for your VDI server. If your network utilization hits 100% during peak periods, all-flash storage arrays might help reduce latency, but you probably need a network upgrade more than faster storage.

The basics of selecting an all-flash storage array

Start with the basics: How many hosts will need to use the storage? Do you support database servers? What about server virtualization, VDI or video streaming, or all of the above? Once you have some data, you can view the vendor's websites, social media and user forums for input into which specific all-flash array (AFA) storage system is likely to be the best fit for your situation. There are other resources that can help with this process, too.

First, most all-flash array vendors employ knowledgeable presale engineers who can help you characterize your storage issues and determine which products may best solve them. They can often help you set up a pilot project with free evaluation versions of their systems.

Second, there are user groups and forums devoted to the topic of AFAs. Most of the major manufacturers have dedicated user groups, as do many applications, including VMware and Microsoft Windows SQL Server. You can pose questions to peers, hear about issues that the manufacturers won't tell you about and learn from other users' mistakes.

Third, even if your project is small and you do not think you need a pilot program, take advantage of the vendors' free trial systems. At least read the product documentation for the AFA storage systems you are considering. There may be features you are not aware of that could help you improve performance in areas beyond your basic objectives.

To get a feel for how this process might work for you, examine three categories of AFA storage products -- high-end enterprise arrays, midrange systems and network-attached storage (NAS) appliances -- and how the products compare between categories. There is plenty of overlap here; some manufacturers' product lines encompass all three categories.

You could also add other categories; split high-end enterprise into NAS and SAN versions, for instance, or look at SMB-oriented systems starting at under $10,000. However, the following three categories will give you a good feel for the range of all-flash storage arrays available and how different configurations of hardware may suit your needs, depending on what kinds of apps you need to support.

High-end enterprise all-flash storage arrays

These are modular systems intended to scale. A minimum configuration is typically at least two controllers and up to dozens of storage nodes. A system may scale out by adding both controllers and storage, or scale up by adding multiple storage nodes per controller. High-end enterprise systems often offer both SAN and NAS functionality, with Fibre Channel 10 GB or faster Ethernet and CIFS/NFS support for NAS features.

You may notice numbers such as 2 million IOPS or 99.9999% reliability, as well as capacities in the petabyte range in vendor advertising. Be aware that these are perfect case scenarios, often requiring a great deal more hardware than the base configuration. You might need four or more controllers (with some systems supporting eight, 12 or 16) to achieve the 99.9999% uptime. And it may require multiple nodes with the maximum number of connections and servers to achieve 2 million IOPS.

On the software side, features that used to be available on only the highest end systems are now standard on nearly every system, from the base configuration on up. These include automated tiering, inline data reduction, snapshots, data protection, encryption, storage management, thin provisioning and even cloud functionality.

There is also a great deal of product overlap in some vendors' portfolios. For example, Dell EMC sells the EMC XtremIO, VMAX and Unity all-flash SAN or unified lines. The XtremIO and VMAX lines are intended to be enterprise arrays with large capacities of storage and speed. The Unity is a midrange unified platform, but its capacity can be expanded to levels larger than the base XtremIO and VMAX configurations.

Hitachi Data Systems Corp. (HDS) sells a wide variety of all-flash models, including the VSP-F400, F600, F800 and F1500, rated at 600,000 to 4.8 million IOPS, and 10 Gbps to 48 gigabytes per second. Capacities range from 280 TB to 40 petabytes (PB). Including the other models that are capable of hybrid flash and HD, there are dozens of systems available. The all-flash models include inline compression, adaptive data reduction (deduplication) and unified SAN/NAS support.

HPE 3PAR StoreServ provides several lines and models, including the StoreServ 20000 and 9000. HPE also sells the XP7, which is a rebranded HDS Virtual Storage Platform system. These HPE systems offer a wide array of all-flash configurations and performance levels. For example, the StoreServ 20000 has 11 base configurations, with many options and extras available, and the 9000 is available in 24 models. These AFA systems range from 3.84 TB to many petabytes, and their performance ranges from hundreds of thousands of IOPS to millions.

The IBM FlashSystem V9000 and A9000 platforms, like the other systems listed here, are available in dozens of configurations, from a base configuration of a few terabytes to petabytes, four to dozens of gigabits, 10 GB or Fibre Channel ports and tens of thousands of IOPS.

NetApp's All-Flash FAS (AFF) arrays support block and file storage and run from the enterprise down through the low end of the midrange. The AFF A700 is the highest end system, scaling to 7.3 PB in an 8U, two-controller node and 44.1 PB in a 12-node cluster (six two-node pairs). The 4U AFF A700s scales to 39 PB raw capacity in a dual-controller system and 17.6 PB in a 12-node cluster. NetApp's AFF A300 and A200 midrange arrays hold more maximum capacity than the A700s, but the A700s has more memory for performance.

Pure Storage and Kaminario developed their systems from the ground up for all-flash, and they do not sell any arrays with hard disk drives.

The Pure Storage FlashArray//X is a new, all-NVMe, all-flash system that exclusively uses NVMe, the fastest type of flash. A single //X70 3U array has an effective capacity of 1.1 PB, with latency around a microsecond and high IOPS and throughput. The system can scale to 15 PB in a rack, and it offers the usual software features, including thin provisioning, deduplication and compression. The FlashArray//X will not be available until the second half of 2017.

The Kaminario K2 scales from 30 TB to 4 PB, from 370,000 to 1.5 million IOPS and offers a wide array of software for deduplication, compression, thin provisioning, snapshots and replication.

Tegile IntelliFlash HD has four models, ranging from 307 TB to 1.8 PB in a 5U system with dual active/active controllers, with eight or 16 ports that can be Gigabit Ethernet, 10 GbE or Fibre Channel. Multiple controllers can be stacked to create larger systems.

Midrange SANs

Most of the high-end enterprise all-flash array vendors sell midrange systems that are smaller in capacity and horsepower than the enterprise arrays. Sometimes, they have the same family name, such as the products in the HPE 3PAR StoreServ line, while others are completely different platforms, like Dell EMC's enterprise and midrange arrays.

The midrange systems can start with one 2U appliance, with the option of adding appliances or higher end models from the same company and managing both the small and large systems through the same administrative console.

Dell EMC Unity All-Flash is a midrange system that offers all-flash and hybrid models. The 300F, 400F, 500F and 600F models offer dedupe, compression, snapshots and effective capacities up to 10 PB.

The 2U NetApp AFF A200 and 3U A300 are midrange offerings, scaling from 8.8 PB to 33.3 PB in two-node controllers, and to 70.5 PB in 12 nodes. NetApp also sells an all-flash product line acquired from SolidFire. The SolidFire SF-Series scales from 4.8 TB to 17.4 TB in single storage nodes with one controller.

The HPE StoreVirtual All-Flash 3200 and 4335 offer dozens of configurations, ranging from 1.2 TB to more than 500 TB, with four ports per enclosure that can be gigabit, 10 GbE or Fibre Channel, and can support up to four enclosures in a cluster, with replication, thin provisioning, snapshots and dedupe.

The IBM Storwize V7000F is a 3U box that offers up to 24 solid-state drives per box, as well as the ability to administer and present multiple boxes as a single system. Boxes can be bought as needed and easily integrated into the existing infrastructure.

The Pure Storage FlashArray//M all-flash system is available in four models, ranging from 30 TB to 1.5 PB. Multiple boxes can be added and administered as a single system.

The Tegile T Series offers a variety of models and sizes, ranging from an effective 22 TB minimum in the T4500, to 1.241 PB max in the T4800. There are corresponding hybrid models in addition to the all-flash versions.

NAS appliances

NetApp and Dell EMC Isilon are well-known NAS systems providers, though the line between NAS and SAN is becoming blurry. Nearly all vendors provide CIFS and NFS services now, and NAS systems can usually support iSCSI and Fibre Channel connections.

The difference between a fully NAS-optimized system and a SAN system with CIFS capabilities, though, can be substantial. One of the key differentiators here is the number of users. A dual-controller NetApp FAS2020 system can handle hundreds of users, while a big system, such as the NetApp FAS9000, can scale to more than 100 petabytes and support thousands of users. SAN systems with CIFS support can be much less efficient than systems initially designed for NAS. Models in this group include the NetApp FAS, Dell EMC Isilon and Pure Storage FlashBlade.

The NetApp AFF A700, AFF A700s and AFF A300 all scale to 24 nodes for NAS, and the AFF A700 holds up to 88.1 TB of raw capacity. The AFF A200 scales to eight nodes and 8.8 PB.

The Dell EMC Isilon F800 is the family's all-flash model. The F800 stores from 96 TB to 924 TB of raw capacity per chassis.

Pure Storage's FlashBlade supports NFS and object storage. It holds 8 TB and 52 TB blades. A fully populated array can hold 15 blades and up to 780 TB of raw capacity.

Just about any vendor included here can create a system that will provide the performance you need for the applications you run. The starting point should not be cost or performance, but the applications you run and your level of comfort with the vendors with whom you are dealing.