A criticism I often hear from industry insiders and ‘experts’ is that the higher cost and TCO (Total Cost of Ownership) of SSD technology is a significant barrier to rapid and widespread enterprise adoption.

Nothing could be further from the truth.

I believe that this stems from the fact that the industry is stuck on using the HDD metric of $/GB and single drive cost as the primary measures of the cost. As I wrote in a previous post, “Storage managers getting wise to prevailing SSD limitations”, looking at historical or single drive cost metrics doesn’t accurately measure solution-level costs. So let’s try this again.

Yes, individual enterprise-class solid state drives (Enterprise Flash Drives) cost more than individual enterprise hard drives. So having stated this fact, let’s also be sure to state the fact that EFDs offer tremendous performance boosts (>100X), and can replace many 15K RPM HDDs. Budget constraints require that enterprises and data centers focus on maximizing both performance and efficiency, so transaction cost ($/IOPS) is also a key metric.

The goal is to provide a storage solution that optimizes for both $/GB and $/IOPS.

Let’s look at a typical data warehousing application from the TPC-C benchmarks (http://www.tpc.org/tpcc/results/tpcc_perf_results.asp). The storage solution must provide 640,000 transactions/minute (320,000 IOPS) for 18 TB of data. With a typical all-HDD solution, this requires:

• 1000 15K 2.5-inch HDDs (short stroked to 18GB)
• 40 rack mounted shelves
• 8000 watts to operate and (an additional) 8000 watts to cool
• Price tag = $ 450,000

Now, let’s look at how a ‘hybrid’ approach combining EFDs and existing HDDs can not only provide a lower transaction cost, but also a lower cost/GB and a lower total cost. This hybrid solution would be configured as outlined below:

Not only does the hybrid approach offer a much lower $/GB and $/IOP (and requires 34 fewer shelves), but the total cost is one-half that of the HDD-only configuration.

Did you catch that?  One-half the total cost.

At the end of the day, the numbers don’t lie. The value proposition of EFDs is simple, it provides ‘more for less’ – more performance for less cost, less power and floor space, and more reliability. And, EFDs can be managed with existing software.

What will IT managers do with all the savings?

Amyl Ahola

The industry is catching on to what I’ve been talking about for some time: flash technology offers tremendous value for the enterprise, yet adoption hinges on addressing the prevailing limitations of existing SSDs first.

This ‘revelation’ appeared in a SearchStorage.com article by Beth Pariseau, “Storage admins mull SSDs at SNW.”  The article quotes multiple storage administrators who all basically believe in the benefits of SSD, but stop short of saying that the technology is ready for prime time.

Here are their top concerns: predictable performance, data integrity, the lack of consistent, industry-accepted SSD benchmarks, and cost.

Let’s quickly look at each of these:

1. Predictable performance – I covered this recently in my “’Predictable performance’ for changing business dynamics” post. This area has traditionally been a challenge for SSDs in enterprise applications because workloads are random and indeterminate. Predictability requires consistent performance, independent of whether reading or writing data, because enterprise applications typically vary the read-to-write ratio between 60/40 and 90/10. Enterprise SSDs should be able to maintain performance across this range.
2. Data integrity – I couldn’t agree more that data integrity features are critical if flash technology is to perform at enterprise levels, and the Data Integrity Field (DIF) standard is an important step in this direction. Yet, today so few storage devices support the DIF standard. Pliant began mapping toward the DIF standard early on, recognizing how important it was for enterprise-class storage systems.
3. Standardized benchmarks – In my post, “SSD jargon and the need for standards,” I listed a number of pivotal questions that must be addressed if the industry is ever to develop more accurate, relevant – and yes, consistent – SSD benchmarks. These include making sure that real performance is measured and that product lifecycle benchmarks are based on true, 100% duty cycle operation. If product life metrics are contingent on usage limitations – e.g., based on a maximum number of writes or writes per day due to limited error management capability – then the benchmarks are virtually useless.
4. Cost – Transaction cost (IOPS per $) is the key SSD metric to consider, not the old HDD industry metric of $/GB. This metric is an irrelevant measure of SSD value as a performance solution, and we expect EFDs (Enterprise Flash Drives) to complement high capacity HDDs to optimize for both $/IOP and $/GB.

With most existing vendors either falling short on a number of these points, or masking the limitations of their devices behind carefully crafted marketing spin, it’s no wonder why some storage admins are still skeptical.

This is why I continue to extol the values of EFDs, a new class of solid state storage devices designed with key enterprise considerations in mind. By definition, EFDs are designed to address all of the above issues.

And, as we prepare to announce availability of our first products shortly, my hope is that our approach will help turn the heads and change the minds of the remaining nay-sayers in the industry.

Amyl Ahola

Pliant’s Greg Goelz is currently featured on the storage site, STORAGEsearch.com.  In the article, Greg shares his list of recommended articles and resources about SSD market trends and technologies.

Check it out!

Amyl Ahola

A recent article by editor Zsolt Kerekes of STORAGEsearch.com entitled, “flash SSD Jargon Explained,” got my attention.  The fact that there is a need to explain the jargon is a reminder that the marketing wizards keep inventing new terms to ‘differentiate’ their products, while confusing most of us and masking issues of real importance to data center operations.   A version of marketing 101: If you have a weakness, flaunt it.

The list of SSD jargon Kerekes cites in the article includes: dynamic leveling, active leveling, static leveling, BCH codes, Reed Solomon codes, write endurance, write amplification, write attenuation, garbage collection, read patrol, wear leveling, read disturb, and program disturb.

Look at the last two.  These are rarely discussed but are among the most important issues to those who care about losing data.  An earlier STORAGEsearch.com article asks the question, “Can you trust your flash SSD specs & Benchmarks?”  The answer can only be ‘of course not!’  At least not until there is some semblance of standardization.  This is especially true when considering using SSDs to meet the performance and reliability demands of enterprise applications.

With this in mind, some questions that should be asked (and answered) about SSD performance and reliability specs and benchmarks are:

1.    What is the real performance?

A simple question but rarely, if ever, addressed in the specifications.  Typical environments are random, 60%-70% read, and 4K/8K blocks.  Not small blocks (512b) to show high IOPs, or large blocks to show high bandwidth.

2.    Is the performance deterministic?

The writing process for flash is inherently slower than reading.  Does the performance drop substantially as a function of the read/write mix or does it stay relatively constant as needed to maintain consistent response times?  Is the performance dependent upon the use of cache (and the associated power loss and recovery issues of volatile cache memory)?

3.    Is the performance sustainable?

What does ‘sustainable’ mean? It is not unusual for performance to degrade as more and more of the device gets written to…it may take minutes or hours, but degradation of 50% or more may occur.

4.    What is the capacity available to the user?

Another simple question, but all SSDs contain more flash than that available for end user data. For example, the additional (or over-provisioned) flash may be used to optimize write performance, provide for spare blocks, CRC codes, ECC codes, and meta data.  Does the stated capacity net this all out?

5.    Are there duty cycle or other limitations on usage in order to achieve/maintain the specifications?

Does the architecture provide for 100% duty cycle, or is the product life contingent on a maximum number of writes or writes per day due to limited error management capability.

Is it assumed there will be ‘adequate’ idle time (what’s that in the enterprise?) to perform the necessary flash management activities?

6.    Are the error management and ECC algorithms powerful enough to correct read disturb and program disturb errors without resulting in excessive rates of uncorrectable errors and/or losing capacity due to bad block mapping?

Error correction approaches which utilize limited ECC to correct random bit failures may not have sufficient correction capability for read/program disturb errors. Correction capabilities may appear adequate but be based on codes, such as the Reed Solomon code, which is great for hard drives but not really applicable to flash failure modes. The lack of idle time for background flash management makes this problematic for many / most SSD architectures.

Kerekes sums it up well: “Better user education about SSDs is a critical factor for the industry to sustain its growth. Design trade offs in products go far deeper than the choice of memory and interface. Being aware that there are other parameters which SSD vendors have implemented well, badly (or not at all) can be the difference between a satisfactory or disillusionary experience.”

What do you think?

Amyl Ahola

Now, here’s someone who really understands the benefits and value of using Enterprise Flash Drives (EFDs) in enterprise IT data centers:  Mark Peters.

Mark covers data center storage and systems for Enterprise Strategy Group.  He was recently interviewed for a SearchStorage.com “FAQ Guide” podcast about the growth in enterprise solid state technology.  (Read the full transcript here)

In the interview, Mark addresses the questions he hears most often from storage administrators about solid state technology, and I have to say that his views are spot-on — particularly regarding the benefits and value of solid state, and the market/business drivers that are making the technology increasingly attractive.

A few of the key points Mark makes are:

1)  I/O performance benefits

“Generically, whatever is most important to a business or enterprise or organization in terms of getting throughput and I/O handled, wherever you need speed, wherever you need a great deal of performance in terms of throughput, then solid state will be great.”

2)  Energy efficiency

“Given that we’re in such challenging economic times, that makes solid state more interesting.  Obviously with my focus on the data center I look at the green aspect of computing as well, and it’s hard to overlook solid state from that perspective.”

3)  Cost-efficiency

“Even in terms of today’s pricing, cost per I/O or the I/O per watt for solid state are already very compelling.”

It’s nice to see Mark (and other industry experts) start to recognize the important and growing role EFDs will play in the future.

Amyl Ahola

PS.  Mark also has a blog with more great info on a variety data center storage issues:  Mark My Words.  I suggest checking it out if you haven’t already.

You don’t need a crystal ball to predict how the global economic slowdown and a prolonged recession will impact IT spending in 2009:  it’s going to be ugly.  Many projects will be delayed, eliminated outright, or at the very least, cut severely in scope. 

This poses a huge problem for enterprise IT managers. Why? 

Quite simply, enterprise information demands continue to increase with no end in sight.  And, data center managers will have to do anything and everything in their power — without making significant new IT capital investments —to keep up with the increasing IT system performance demands. 

Failure to do so will be unacceptable, so what are the options?

Two things come to mind:  1) optimizing existing IT systems for increased performance; and 2) significantly reducing the energy consumption of power-hungry high RPM hard disk racks.  Is this difficult? 

It may be easier than one thinks and requires no change to the existing infrastructure, management software or systems.  By adding Enterprise Flash Drives (EFDs) to handle the performance workload of many spinning hard drives, both goals can be achieved.  The high performance of the EFD enables more I/Operformance and flexibility to meet peak periods and growing demands.  By combining EFDs with high capacity HDDs, today’s storage racks can be reduced to storage shelves saving power (up to 80%), space and money. 

I predict that beginning in 2009, EFDs will be a key tool for enterprise IT managers to survive the economic turmoil while optimizing their existing storage systems.

And, let’s face it, it’s time for a change to the traditional approach to high-performance storage solutions. 

Interested to hear your feedback, so please feel free to comment.

Amyl Ahola

It’s clear to many industry experts that the enterprise storage landscape is changing dramatically.  And, as I’ve said, soon just about every enterprise data center in the world will be using enterprise flash drives (EFDs) for at least a portion of their data storage needs due to the accelerated requirements for higher levels of I/O performance, as well as the growing pressure to cut energy costs.

I was recently published in Systems Management News, so check out the article for greater detail.Click to link here:  http://www.sysmannews.com/link/32853. 

I’m curious to hear what you think, so feel free to comment.

Amyl Ahola

My guess is that today’s gaggle of green events, speeches and articles will focus on inspiring each of us to raise our environmental consciousness by rethinking the way we use energy.  No question, a noble and necessary exercise. 

However, one topic that I’m afraid may not receive its fair share of MSM attention is the rapidly growing problem of data center power consumption. 

Here’s the issue.  According to a recent report (http://www.energystar.gov/ia/partners/prod_development/downloads/EPA_Datacenter_Report_Congress_Final1.pdf), servers and data centers account for about 1.5 percent of all U.S. energy consumption, or 61 billion kilowatt-hours (kWh).  This is more than the electricity consumed by the nation’s color televisions in a year, and about as much energy used to power 5.8 million average U.S. households.  And, at the rate our digital information requirements are growing, server/data center energy consumption will nearly double to 100 kWh by 2011, which represents about $7.4 billion in annual electricity costs. 

So what can we do to move rapidly to greener data centers?  The worst offending part of the system, the misuse of HDDs, should be among the first to be dealt with.  The fact is that many IT managers are using 3 to 4 times more HDDs than they need from a capacity perspective just to meet growing I/O performance requirements.  This “over provisioning” does not only fail to meet I/O performance needs as I noted in earlier posts, but it’s probably one of the most inefficient uses of IT technology I’ve ever seen.  Talk about a waste of space and power (not to mention money)!

With data centers under constant pressure to operate more efficiently and reduce costs, this type of waste is ridiculous, especially when there are other viable alternatives available.  One technology that deserves serious attention is the Enterprise Flash Drive, which is based on solid state technology to offer extremely high data I/O performance. 

Here’s an example of the benefits of deploying EFDs in the enterprise, without breaking the bank.  A hybrid solution combining existing hard drives (preserving some of the initial investment) with selectively deployed EFDs can greatly enhance I/O performance while eliminating the need for HDD over-provisioning.  Best of all, this type of approach can slash data center energy consumption – up to 80 percent in some cases.

Let’s face it, enterprise data centers will continue to push the envelope in terms of performance and capacity requirements.  The trick is finding ways to meet these demands in the most efficient and cost-effective way possible, and EFDs can be a great option for many organizations.

Amyl Ahola 

Who could ask for more than seeing a new storage industry product announcement to highlight the points you’ve been trying to make?
 
I found myself in that position, and was quite surprised (well not really surprised…more like incredulous) to see a recent announcement of what had been frequently referred to as the Seagate “brick” project (not related to MiniScribe), but minimally disguised within a Seagate-funded private company.  The product that was announced is another version of a sealed unit consisting of multiple hard drives “purpose-built to maximize performance and reliability.”  The announcement makes it clear that many new techniques must have been employed to achieve “self-healing,” and to enable the product to essentially repair itself in place “to the equivalent of a fresh, factory-manufactured drive.”  Wow!  I will leave it up to people smarter than me to respond to this.

What I’d like to discuss is the price performance aspect of this announcement.  The systems tested were fully mirrored, making comparisons never quite “apples to apples.”  However, one needs to keep in mind that the MTBF of the drives employed require mirroring to reach any reasonable reliability level.  While I could not find any real price or performance data on the company’s web site, the reference to their SPC benchmarks provided considerable data.
 
From a pricing standpoint, the 1.03TB configuration sells for more than $36 per gigabyte (after a 40% discount from $60/GB)…and, flash-based SSD at $30/GB is considered expensive?
 
This benchmark is also said to be record-breaking with the lowest cost per SPC-1 IOPs.  I’m not suggesting that $36/GB is unreasonable, only that it illustrates the true cost of hard drives in high-performance environments.  A closer look at the benchmark is even more telling.  This “record-breaking” performance correlates to a response time of nearly 30 milliseconds.  In fact, response time increases dramatically starting at about 50% of the max IOPs, which is certainly troublesome for high transaction-rate systems.

This project was started a few years ago, apparently to address the growing price, performance and reliability gap in enterprise applications, as we have been talking about, and to hold off the encroachment of solid state storage devices.  However, with today’s technology, well designed Enterprise Flash Drives will not only be lower in cost per GB, less than 1/4th the cost per IOP, and more reliable.  And, did I mention power:  EFD’s will be well less than 1/100th the watts per IOPs.  I cannot help but be reminded of the Anderson Cooper segment on CNN:  “What were they thinking!”

Amyl Ahola

The dramatic reductions in HDD cost per GB have resulted in many system/storage architects (and application/operating system programmers) treating primary storage as though it is free.

Some of the results are:

• Exponential increases in the size of operating systems and applications
• Mass deployment of low-end and midrange servers with multiple copies of data (and applications)
• Over-provisioning of storage to satisfy future needs projections (which also likely adopt the concept of free storage)
• Adoption of power-hungry DRAM cache appliances to mask HDD performance shortfalls
• Over-provisioning of HDDs to mask HDD performance shortfalls

These all result in inefficient use of storage that has many costs, not the least of which is the increasing cost of energy consumption.  Some of the energy data becoming available paints a sobering picture:

• Data centers account for 1.5% of ALL U.S. electrical consumption, and this is expected to double in a few years
• Power consumption per $1,000 of server spending has increased by a factor of 4 since 2000
• Power failure and availability is expected to halt data center operations at more than 90% of all companies over the next few years
• Fifty percent of current data centers will have insufficient power and cooling capacity this year

HDDs are clearly not the only contributor to the rapid acceleration of data center power consumption, but their inefficient use is likely one of the largest contributors.  Data that suggests more than one third of data center power consumption is storage related.

Trends and techniques such as consolidation, virtualization and thin provisioning should all contribute to improved efficiencies.  But while doing so, these approaches will put increased performance demands on the HDDs.  The result:  an increased need for higher performance (i.e., higher RPM……read that as ‘power consuming’) drives and even further over-provisioning for performance – and therefore once again increased energy consumption.

It’s time for new metrics to be considered in the data centers, which take into account energy usage to aid the system designers as they optimize their systems.  Several metrics are identified at the www.greendatastorage.com website; examples cited include activity per watt, such as transactions/Watt, IOPs/Watt, and bandwidth/Watt.

I believe that Enterprise Flash Drives (EFDs) will play a major role in reversing these trends. EFDs can provide over 1000x improvement in IOPs/Watt, and an order of magnitude or more improvement in bandwidth/Watt over the highest performing HDD’s.

Amyl Ahola