What is All-Flash-Array (AFA)?

The world of technology, and storage in particular are continually looking for ways to meet the demands of fast data retrieval and low response time needs. To help meet these needs, something called an “all-flash-array" came along - more commonly known as “AFA”. 

It's a type of data storage system that utilises solid-state-drives (SSDs), that we know all so well about at Simms. It's exclusive made for SSDs, unlike traditional storage like hard-disk-drives (HDDs), which relies on spinning disk. By using flash memory, AFAs deliver much faster read and write operations. In doing so, application performance will sky rocket and the overall system will see better responsiveness. 

Who were the first to incorporate it?

The concept started way back, further than you think. The concept of and term “all-flash array” started in the 1980s and has evolved over time. It's when SSDs came into the market in 2000s that it significantly started to develop.

Early players to develop were Texas Memory Systems and Pure Storage. Since then however, many major storage vendors have began developing their own all-flash array offerings. These include Dell, Fujitsu and NetAPP, with some of the leading products including the following:

• Dell EMC PowerStore
• Dell EMC PowerVault
• Fujitsu Eternus
• Hewlett Packard Enterprise (HPE) Alletra
• Hitachi Vantara Virtual Storage Platform
• IBM FlashSystem
• Tintri N-Series
• Tintri H-Series
• NetApp All-Flash FAS
• NetApp SolidFire family -- including NetApp HCI (hyper-converged infrastructure)
• Pure Storage FlashArray
• Pure FlashBlade
• Huawei OceanStor

Differences between all-flash array and disk

There are several key aspects in how AFA differs from the traditional disk-based storage:-

Performance: It's not everything, but it's a top key aspect. AFAs offer much better performance compared to spinning disk. Faster data access times, lower latency, and higher throughput. Simple to see why it's more favoured.

Storage medium: This is probably the primary difference. It uses SSD compared to HDD. SSD is based on flash technology where HDD is reliant on traditional disk-based storage systems which rely on spinning hard disk drives (HDD) with magnetic platters. 

Reliability: This is really just pointing to the SSD vs HDD argument. SSDs are “generally” more reliable than HDD". They have no moving parts. HDD can be subject to mechanical failures, where as SSDs have no such vulnerabilities when it comes to the spinning platters. 

Space & Scalability: AFAs tend to have a smaller physical footprint. SSDs are more compact and lightweight than traditional HDDs. Density at a higher level within the same physical space allows businesses to store more data in smaller footprints leading to data centre savings. SSDs can easily scale compared to traditional HDD.

The cost of flash is still higher than that of spinning desk. However, developments in MLC flash, TLC and 3D NAND has dramatically lowered the TCO of this product. Such technologies are allowing businesses to benefit mainly from the density advantages mentioned above. All without the cost in involved in shrinking NAND cells.

What considerations should you make for buying AFA?

A good question: is your business and IT setup there yet? Do you need to worry about all-flash array at this stage of your journey?

There are a number of factors we suggest you consider before purchasing all-flash array:-

Workloads: It's all about your environment(s) and workloads. Whilst AFAs are exceptional for delivering superb performance and high IOPS, consider your workload requirements and expectations. Metrics to look for include: sustained performance, latency figures and random and sequential read/write speeds. 

Examples of workloads suited for AFA are: Databases, Virtualization, Analytics, Business Intelligence

Capacity: What is your required capacity in terms of raw capacity - the amount of physical storage available? And usable - storage available after factoring in data reduction technologies like deduplication and compression? At this point you need to consider what your future growth projections are to ensure the all-flash array can house your ever-expanding storage needs.

Availability and Reliability: Does the systems availability guarantee the ability to handle failures without messing with ops? Form redundancy, look for RAID protection and other features like hot-swappable drives. 

Management and Monitoring: You should be looking for user-friendly management interface that gives total visibility into your performance, capacity use and system health. What's more, automation features, and integration with existing management tools can give a greater feel to your operations. 

Scale: Scalability is key. Your business grows; your requirements for scale follow. You need to understand and determine at before to ensure the AFA integrates well with your current infrastructure, Look out for things like “non-disruptive” scalability. You'll need the capability to add new drives and/or nodes with minimal, or zero downtime. 

Cost-effectiveness: At Simms, we hit the TCO drum hard. It's important. The Total Cost of Ownership of the lifespan of your AFA must work. AFAs will likely have a higher upfront cost. However, you must factor in long-term benefits of basically - all of the above. Understand and assess the pricing model, including software licensing, and maintenance. 

Future-proofing: And finally, the need to consider the pace of technological advancement is very important. Can the AFA's ability to adopt future advancements? Think about compatibility with up and coming storage protocols. Also, align with the vendor - are the committed to innovation?

What is hybrid array?

Another type of storage system is a “hybrid-array”. It's a system that combines both SSD and HDD in a single system. Why? To provide balance between performance and capacity. It can do this by truly leveraging the strengths of both technologies. 

How does it work? The SSDs are usually used as a cache or a tier of high-performance storage. The HDDs serve as the main storage tier for the capacity-intensive data. Dynamically, the SSD cache will store the most accessed data to boost the read and write op. What does this do? Well it improves the overall performance and reduces the latency. 

It all comes down to understanding your very own requirements when choosing between an all-flash array and a hybrid-array. On top of this, consider performance, budget and capacity. All-flash arrays essentially work best for mission-critical workloads that demand a very constant low-latency output. While a hybrid array will offer a true cost-effective solution for your operations that strikes a fine balance between performance capacity.