 | Ariel Lindenfeld Director of Community Management at IT Central Station |
The all flash storage array has matured to the point where it is now powering much of the growth in the enterprise storage business. Advances in the design, performance and management capabilities of solid state drive (SSDs), coupled with declines in cost, make flash storage viable for many workloads. The category includes NAND flash, SSD SATA, tiered storage and NAND flash memory. Enterprise storage is relentlessly demanding, though, so potential buyers need to think critically about what makes the best choice of flash array.
IT Central Station members who have experience with solid state storage emphasize ease of use as an essential selection criterion. They suggest asking if daily and weekly tasks can be completed easily. For example, how difficult is it to add or change storage volumes and logical unit numbers (LUNs)?
Some popular user comparisons:
Performance also matters, though many members comment that virtually all flash drives offer strong performance. Look closely at (IOPS), reduced footprint and lower power usage. In addition, they suggest asking whether one needs an array with larger block size and one where compression and de-duplication can be enabled or disabled on select volumes. But, reviewers add, it’s important to understand one’s data. For example, with an Oracle database, block size will matter a great deal.
Data reduction and data management capabilities factor into many comments about solid state hard drive selection. Deduplication and compression help manage storage growth. Reviewers also point out that recovery abilities matter with solid state drives. No one wants data loss if the storage array powers down suddenly.
Data storage companies offer many different reporting options. IT Central Station members stress the importance of this feature. For instance, do reports show the business the efficiencies provided by the storage infrastructure? Or, do they report on the specifics of data compression, de-duplication rates, I/O Latency reports and so forth.
Customers should consider not only performance, which is really table stakes for an All Flash Array, but also resilience design and data services offered on the platform. AFA is most often used for Tier-1 apps, so the definition of what is required to support a Tier-1 application should not be compromised to fit what a particular AFA does or does not support. Simplicity and interoperability with other non-AFA assets is also key. AFA's should support replication to and data portability between itself and non-AFAs. Further, these capabilities should be native and not require additional hardware and software (virtual or physical) to support these capabilities. Lastly, don't get hung up on the minutia of de-dupe, compression, compaction, or data reduction metrics. All leading vendors have approaches that leverage what their technologies can do to make the most efficient use of flash and preserve its duty-cycle. At the end of the day, you should compare two rations: Storage seen by the host\storage consumed on the array (or another way, provisioned v. allocated) and $/GB. These are the most useful in comparing what you are getting for your money. The $/IOPS conversation is old and challenging to relate to real costs as IOPS is a more ephemeral concept that GB, plus.
Primary requirement for me is the data reduction using data de-duplication algorithms. Second requirement is SSD's wear gauge. i need to be sure that SSD's installed in a Flash Array will work as many years as possible. So the vendor who has the best offering in those 2 topics has the best flash array.
It depends on your requirements. Are you looking at Flash for Performance, ease of use, or improve data management.
Performance; you likely want an array with larger block size and one where compression and de-duplication can be enabled or disabled on select volumes.
Data reduction or data management: De-duplication and compression help manage storage growth however; you do need to understand your data. If you have many Oracle databases then Block size will be key. Most products use a 4-8K block size. Oracle writes a unique ID on the Data blocks which makes it look like unique data. If your product has a smaller block size your compression and de-duplication will be better. (Below 4K better but performance may suffer slightly)
De-duplication: If you have several Test, Dev, QA databases that are all copies of production de-duplication might help significantly. With this if de-duplication is your goal you need to look at the de-duplication boundaries. Products that offer array wide or Grid wide de-duplication will provide the most benefit.
Remote Replication: If this is a requirement you need to look at this carefully each dose it differently, some products need a separate inline appliance to accommodate replication. Replication with no rehydration of data is preferred as this will reduce Wan Bandwidth requirements and Remote storage volumes.
Ease of use: Can the daily weekly tasks be completed easily, how difficult is it to add or change storage Volumes, LUN’s, Aggregates. Do you need Aggregates? Can you meet the RTO/RPO Business requirements with the storage or will you need to use a Backup tool set to do this? You should include the cost of meeting the RTP/RPO in the solution cost evaluation.
Reporting: you need to look at the caned reports do they have the reports you need to sufficiently mange your data. And equally important to they have the reports needed to show the business the efficiencies provided by the storage Infrastructure. Do you need bill back reports? (Compression, de-duplication rates, I/O Latency reports, ect..).
Understanding your particular use case is key to selecting the proper technology for your environment. We are Big Data, Oracle, Data Warehouse. NON-OLTP, So we are hyper sensitive to performance and HA. Flash and Flash Hybrid are the future for the datacenter, but there are varying ways of skinning this cat. so pay close attention to the details. for me HA is paramount. our storage must be NDU in all situations. Performance is important but we are seeing numbers well in excess of anyone's requirements. So what's next? sustained performance. Write Cliff issues, how is this addressed? datacenter cost if your a co-lo is important so having a smaller foot print and lower KW's should be considered. Then of course cost. becareful of the usable number. often de-duplication and compression is factored in with the marketing, So POC is important to understand true usable.
I go back to my original statement, understanding what YOUR company needs is the most important piece of data one should take into the conversation with any and all of the suitors.
storage virtualization and the ability to tailor the storage solution to needs of the end user and associated compute resources is the biggest factor. Being able to easily implement tiers of storage performance is key to being more efficient with the money spent on storage.
AFA's have two major advantages over spinning disk - latency and IOPS - so you must understand your workload before jumping into an AFA selection process. Today, the AFA costs 3-5x more than a traditional array. When that price delta narrows to 50% more, I will probably be All flash. Note that as we get to "all flash everywhere" new Hyper-converged architectures will also figure prominently in my AFA analysis.
With the current gap in pricing however, we must engineer a solution for a need. Quantify the need - am I providing EPIC for a 5000 person hospital, analytics, transaction processing etc? What is the critical gating factor and what are the target SLA's? Do I need more IOPS, more throughput, lower latency? Will going to an AFA bring my response time down from 50ms today to 10ms tomorrow? Do I need to remember I have a 100ms SLA? As many note above, AFA's excel in many critical performance areas over traditional arrays - but I don't start with the array - I start with the workloads and what level of service my consumers require.
How many IOPS are you averaging right now? Most organizations have far less IOPS than you would think. If you're looking to just speed up some apps, then use flash array for compute and SAN for long term storage. Or better yet, go with a high end, easy to scale out hyperconverged system and get the best of both worlds! Look for good dedupe and compression numbers.
There is not really any one single thing to consider. These systems are complex for a good reason and the overall outcome will only be as good as the sum of all moving parts....
1. How many disks and therefore how many total IOPS are available?
2. What class of SSD (SLC, cMLC etc)?
3. Are the controllers able to deliver the full capability of the disks behind them?
4. Are the controllers able to flood the interconnects in-front of them?
5. Are there enough controllers to prevent down-time during failure or maintenance without significant degradation of performance?
6. Do the software smarts of the system provide added benefits such as dynamic prioritization of presented volumes allowing you to deliver multiple classes of storage from a single medium?
7. Can the controllers cope with running these software smarts at full speed without affecting the data transport?
And most importantly, perhaps this is the single most important thing...
1. What is the ecosystem behind the storage, i.e. the vendor and their overall capability to patch known issues, properly test releases before publishing them, effectively communicate changes and give you confidence in the long term operation of the SAN. Do they have local support and is it of high quality?