As a follow up to the report, Gartner Fellow Daryl Plummer is hosting a complimentary Webinar on May 20 – Cool Vendors 2010: Staying Cool in Economic Heat – to review the 2010 Cool Vendors, and discuss specifically how each company is poised to positively impact the IT market.

We were thrilled that Plaint was recognized among this elite group of innovators for our Enterprise Flash Drives, and I encourage you to check out the free Webinar.

The Webinar will be held twice on Thurs., May 20, and you can register online at the following links:

Register for 9 a.m. EDT/6 a.m. PDT session – https://www1.gotomeeting.com/register/933461200
Register for Noon EDT / 9 a.m. PDT session – https://www1.gotomeeting.com/register/530216081

Hope you enjoy!

Greg

The seminars have been held in cities across North America (Toronto, Montreal, Boston, Bethesda, and Minneapolis), and the final one is scheduled for this Thursday, Dec. 3, in Milpitas, CA. Four SSD suppliers, including Pliant, will be presenting on the multiple benefits of adding SSDs to the storage infrastructure.

Not surprisingly, there’s quite a bit of expectation and discussion at the seminars that SSDs can deliver significantly higher I/O performance than hard drives. However, what’s surprising to me, having done five of the six seminars, is that people are already talking about “performance droop in SSD over time.” One of the vendors even stated, “fresh-out-of-box performance is different than steady-state performance.”

Now, I will spare you the discussion on how garbage collection affects SSD performance over time, as there are already plenty of articles on this subject. What is most troublesome is that performance droop should not occur at all. Solid state drives are supposed to alleviate performance bottlenecks, not introduce new ones. As such, a properly designed SSD controller should and must have sufficient horsepower so that a critical function like garbage collection will not impact I/O performance.

While we’re on the subject of performance, let’s talk about scalable performance.

Advanced interfaces, such as Fibre Channel (FC) and Serial Attached SCSI (SAS), provide access to two ports. For years, the secondary port has been relegated to sitting idle, used only when the primary port failed.

That’s a shame…and a waste, in my opinion.

Both the FC and SAS interfaces allow performance to scale when both ports are actively used. Given the fact that solid state drives are not physically constrained by a single read/write head, one should expect to scale performance by reading and writing to both ports at the same time!

The below charts illustrate the point:

You paid for both ports already. Why not actually use both?

If you would like to learn more about “scalable performance” and how you can best implement enterprise SSD storage in your IT infrastructure, I invite you to join me and the Bell Micro team at the seminar this Thursday. It will be held at the Crowne Plaza Hotel in Milpitas, CA.

You can find more detailed info here:  http://www.bellmicro.com/ssd/seminar.asp.

I look forward to seeing you there!

C.T. Chu

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

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

Check it out!

Amyl Ahola

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

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

Predictable performance has traditionally been a challenge for SSDs in enterprise applications because workloads are random and indeterminate. This means that predictability requires consistent performance, independent of whether reading or writing data, as enterprise applications typically vary the read-to-write ratio between 60/40 and 90/10.  Ensuring that predictable performance is maintained while the workload changes is another example of how an Enterprise Flash Drive (EFD) offers differentiation from traditional SSDs. 

A performance comparison (IOmeter-based) between a well-publicized ‘enterprise’ SSD and the new Pliant EFD illustrates this difference.  From the chart, you can see how the ‘enterprise’ SSD(I) performance drops by over 80% as the read/write ratio changes. The Pliant EFD maintains its performance across the range from 100% reads to a 50/50 read/write ratio. This is because the Pliant EFD can read and write simultaneously to the drive and therefore offer substantially better and predictable performance for these demanding applications. Traditional SSDs and HDDs can only perform one read or write at a time. 

The bottom line: EFDs enable enterprises to achieve higher I/O performance, maintain performance predictability with changing workloads, offer higher levels of service quality, and dynamically address changing business requirements without adding additional hardware.   

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

Amyl

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

However, as with any new technology, it takes some time for the concept to catch on and for the industry to understand how the technology works and how it can solve real IT and business problems.  So, under the heading of “Industry Education,” I’m very excited that there is an EFD Wikipedia (www.wikipedia.org) definition that clearly outlines EFD benefits, characteristics and applications. 

Take a look:  http://en.wikipedia.org/wiki/Enterprise_Flash_Drive

The great thing about having a universal EFD definition is that it will allow any IT or storage professional to easily access a real-time, detailed explanation of the technology.  Also, because Wikipedia is in the public domain, the EFD definition will evolve as the market grows and the technology advances – making it always relevant to the challenges and issues IT managers will face now and in the future.

Amyl Ahola