All-Flash Array Frequently Asked Questions
Is all-flash enterprise storage expensive?
The real answer to this question depends on how you look at it. From a raw $/GB price comparison, flash is more expensive than traditional enterprise disk at initial purchase. However, this is not the only cost that should be taken into consideration. Flash-based storage can support data reduction technologies, such as in-line deduplication and compression, so depending upon the applications being supported, less overall capacity may be required to store a given amount of content.
Also, given the higher performance of flash, the cost per operation such as $/transaction or $/IOPS can be significantly lower. Finally, an all-flash solution requires less power, cooling, and space in the data center and therefore it will have a lower operating cost than disk. When the total costs over the lifetime of the flash storage are calculated, flash will be on par with or below that of enterprise disk.
What are the benefits of all-flash storage for the data center?
The key benefits of all-flash storage are higher performance and lower total cost of ownership (TCO). With faster access to data, businesses can reduce time to market for new products, deploy business applications that handle high-volume transactions, effectively manage large production databases and customer service apps, and efficiently manage online billing applications to gain more business insight. The end result is that flash can allow businesses to leverage IT to gain economic and competitive advantages.
Learn more about how flash can become a strategic part of your data center architecture (downloadable whitepaper on an all-flash data center) to maximize your ROI and lower your TCO.
What are the differences between all-flash and disk storage for enterprises?
Flash is a silicon-based technology, offering significantly higher performance and reliability than traditional disks. Further, flash can support data efficiency technologies such as inline deduplication and compression, which can allow flash to store data in less space than disk. Flash also requires less power, cooling and data center space than disk drives. The value of flash is that it can enable businesses to obtain greater value and competitive advantage from their IT investment.
What are the differences between all-flash and hybrid storage?
Hybrid storage uses both flash and disk, with hot data residing in the flash. The aim is to offer a solution that is lower in price than an all-flash array while delivering performance improvements over disk. The challenges with hybrid storage include unpredictable performance levels due to which tier the data resides on at the moment (disk vs. flash), increased flash wear due to the movement of data between flash and disk, and overall lower performance than an all flash array.
All-flash storage has only flash media with no hard disks. That means data always resides on flash and delivers consistent, predictable performance for every request.
What is the difference between SSD-based and purpose-built all-flash arrays?
The raw flash technology found in an SSD or a purpose-built all-flash array is the same, but the similarities stop there. Functionally, an SSD is a hard disk drive that has replaced spinning platters with a solid-state (flash) storage medium. The same interfaces (SAS, SATA, etc.) that were designed for HDDs are retained for SSDs, which means that you can interchange the drives within an array. It also means that you can only access the flash the same way you would an HDD. Thus, this becomes the smallest unit in which the array can interact with the flash; it’s limited to the drive level.
With a purpose-built all-flash array, all of the flash chips are treated as a single pool of storage that can be manipulated at the die level, not the SSD level. By eschewing decades-old hard disk protocols the array can achieve more predictable performance at lower latency with much higher flash endurance. It’s only possible to unlock the full potential of flash by designing a system around it, not forcing it to conform to the limitations of hard drives.
In addition, issues related to data locality or hot data residing within a single SSD are dealt with by spreading data evenly across all of the flash to achieve a higher level of parallelism, predictability, and performance.
Learn more in this short article, SSD-Based vs Purpose-Built All-Flash Arrays.
Is all-flash storage suitable only for high-performance requirements?
While flash was once originally deployed to support high performance applications, with the dramatic decrease in costs this is no longer the case. The combination of purpose-built all-flash arrays being able to efficiently support mixed, multiple workloads and the decline in the effective cost of flash to at or below that of enterprise disk, flash is now ideal for primary storage and it has higher, more predictable performance.
Do I need scale-out or scale-up?
Scale-up constitutes adding capacity to meet growing demand while scale-out increases both capacity and performance. Scale-up is an effective solution only until the storage controllers are no longer able to meet SLAs with added capacity. Traditional scale-out may have limitations in how it is implemented or in reliability.
Solutions, such as Violin Scale Smart™, give the user greater flexibility in how they scale while still meeting performance and availability needs. Read more in this short article, Scaling with All-Flash Storage Solutions.
Is always-on data reduction good or bad?
The value of always on data reduction is dependent on the application being used. With an application that benefits greatly from data reduction, such as VDI, then it can be a useful technology. For those applications where data reduction is simply additional overhead or worse a performance impediment, such as a database, then always on data reduction is not beneficial. Since most environments will have a mix of workloads, a storage solution with the flexibility to turn data reduction on or off at the application level would be the best choice.
Is flash really a replacement for spinning disks?
The simple answer is yes; flash really is a replacement for traditional hard disks in the enterprise. Pricing and features are two major factors contributing to this shift. An all-flash solution with rich data management and protection features can now be purchased for the same or lower effective price than enterprise disk solutions and offers a lower TCO.
Will flash technology be replaced by something else in the near future?
There is always something new around the corner. Silicon companies are spending billions of dollars in advancing innovations in flash media, mainly around increasing density and lowering price. Like the disk drive, flash will be around for many years to come and anything new to market could take many years before it becomes a viable solution.
Are all-flash arrays difficult to implement and manage?
As with anything, it depends on the product in question. Some all-flash arrays are much simpler to implement and to manage than others. With a properly designed configuration tool, the storage administrator no longer has to deal with complex tasks such as topology resolution and discovery in global multi-site architectures. For example, using Violin Systems’s Simple Setup Utility, a single flash array can be configured in under a minute and then provisioned using an intuitive management console. Further, with Symphony™ you get a holistic view of all of your Violin Systems storage within a single console.