NVMe (Non-Volatile Memory Express) over Fabrics is of tremendous interest among storage vendors, flash manufacturers, and cloud and Web 2.0 customers. Because it offers efficient remote and shared access to a new generation of flash and other non-volatile memory storage, it requires fast, low latency networks, and the first version of the specification is expected to take advantage of RDMA (Remote Direct Memory Access) support in the transport protocol. Many customers and vendors are now familiar with the advantages and concepts of NVMe over Fabrics but are not familiar with the specific protocols that support it. Join us on January 26^th for this live Webcast that will explore and compare the Ethernet RDMA protocols and transports that support NVMe over Fabrics and the infrastructure needed to use them. You'll hear:

• Why NVMe Over Fabrics requires a low-latency network
• How the NVMe protocol is mapped to the network transport
• How RDMA-capable protocols work
• Comparing available Ethernet RDMA transports: iWARP and RoCE
• Infrastructure required to support RDMA over Ethernet
• Congestion management methods

The event is live, so please bring your questions. We look forward to answering them. Update: If you missed the live event, it's now available  on-demand. You can also  download the webcast slides.

by Marty Foltyn SNIA on Storage continues its preview of SNIA Tutorials at the Storage Visions Conference, a partner program of CES held on January 3-5, 2016 at the Luxor Hotel in Las Vegas.  “SNIA Education Day” is held on afternoon of the pre-conference day at Storage Visions – January 3, 2016 – and is designed to give attendees the opportunity to learn about important storage topics on depth with leading industry speakers. Five tutorials will be presented on the SNIA Education Day.  In the December 17th SNIA on Storage blog, we featured the  tutorial which examines the conflict between privacy and data protection as illustrated in the European Union, but really applicable worldwide. In the December 18 blog, we previewed the Practical Online Cache Analysis and Optimization tutorial. In the December 21 blog, we examined Massively Scalable File Storage – the Key to the Internet of Things. And in the December 22 blog, a tutorial in a new research area - Fog Computing - was explained. Today we preview the final tutorial of the SNIA Education Day - Implementing Stored-Data Encryption, presented by Dr. Michael Willett of Bright Plaza. Data security is top of mind for most businesses trying to respond to the constant barrage of news highlighting data theft, security breaches, and the resulting punitive costs. Combined with litigation risks, compliance issues and pending legislation, companies face a myriad of technologies and products that all claim to protect data-at-rest on storage devices. This SNIA Tutorial will answer the question "What is the right approach to encrypting stored data?". The Trusted Computing Group, with the active participation of the drive industry, has standardized on the technology for self-encrypting drives (SED): the encryption is implemented directly in the drive hardware and electronics. Mature SED products are now available from all the major drive companies, both HDD (rotating media) and SSD (solid state) and both laptops and data center. SEDs provide a low-cost, transparent, performance-optimized solution for stored-data encryption, but SEDs do not protect data in transit, upstream of the storage system. For overall data protection, a layered encryption approach is advised. Sensitive data (eg, as identified by specific regulations: HIPAA, PCI DSS) may require encryption outside and upstream from storage, such as in selected applications or associated with database manipulations. This tutorial will examine a ‘pyramid’ approach to encryption: selected, sensitive data encrypted at the higher logical levels, with full data encryption for all stored data provided by SEDs. SNIA Tutorial presenter Dr. Michael Willett serves as a consultant on the marketing of storage-based security and is currently working with the Bright Plaza executive team to promote the Drive Trust Alliance, whose mission is to promote adoption of SEDs in the marketplace. Dr. Willett received a Bachelor of Science degree from the US Air Force Academy (Top Secret clearance) and a Masters and PhD in mathematics from NC State University. After a career as a university professor of mathematics and computer science, Dr. Willett joined IBM as a design architect, moving into IBM's Cryptography Competency Center. Later, Dr. Willett joined Fiderus, a security and privacy consulting practice, subsequently accepting a position with Wave Systems. Recently, Dr. Willett was a Senior Director at Seagate Research, focusing on security functionality on hard drives, including self-encryption, related standardization, product rollout, patent development, and partner liaison.  Dr. Willett also chaired the OASIS Privacy Management Reference Model Technical Committee (PMRM TC), which has developed an operational reference model for implementing privacy requirements. Most recently, Dr. Willett worked with Samsung as a storage security strategist, helping to define their self-encryption strategy across Samsung’s portfolio of storage products. SNIA is a proud sponsor of the Storage Visions Conference, a partner program of the Consumer Electronics Show (CES).  Storage Visions, held in Las Vegas right before CES on January 3-5, 2016, is the place to explore the latest information on the rapidly evolving technology of digital storage and how it impacts consumer electronics, the internet of things, and storage in the cloud. If you have not registered for Storage Visions, head over to http://www.storagevisions.com for the conference preview.  Take $100 off your registration with the link:  https://sv2016.eventbrite.com/?discount=onehundredoff_67349921

by Marty Foltyn SNIA on Storage continues its preview of SNIA Tutorials at the Storage Visions Conference, a partner program of CES held on January 3-5, 2016 at the Luxor Hotel in Las Vegas.  "SNIA Education Day" is held on afternoon of the pre-conference day at Storage Visions - January 3, 2016 - and is designed to give attendees the opportunity to learn about important storage topics on depth with leading industry speakers. In the December 17th SNIA on Storage blog, we featured a tutorial which examines the conflict between privacy and data protection as illustrated in the European Union, but really applicable worldwide. In the December 18 blog, we previewed the Practical Online Cache Analysis and Optimization tutorial. In the December 21 blog, we examined Massively Scalable File Storage - the Key to the Internet of Things. Today's blog provides a research perspective on "Fog" Computing and its Ecosystem - providing data, compute, storage, and applications services to end users - presented by Professor Ramin Elahi of the University of California, Santa Cruz. The distinguishing Fog characteristics are its proximity to end-users, its dense geographical distribution, and its support for mobility. This SNIA Tutorial will discuss how services are hosted at the network edge or even end devices such as set-top-boxes or access points, which therefore alleviates issues the IoT (Internet of Things) is expected to produce, such as reducing service latency and improving QoS, resulting in a superior user-experience. Fog Computing supports the emerging Internet of Everything (IoE) applications that demand real-time/predictable latency (industrial automation, transportation, networks of sensors and actuators). Thanks to its wide geographical distribution the Fog paradigm is well positioned for real time big data and real time analytics. Fog supports densely distributed data collection points, hence adding a fourth axis to the often mentioned Big Data dimensions (volume, variety, and velocity) SNIA Tutorial presenter Ramin Elahi, MSEE, is an Adjunct Professor and Advisory Board Member at UC Santa Cruz Silicon Valley. He has taught Data Center Storage, Unix Networking and System Administration at UC Santa Cruz and UC Berkeley Ext. since 1996. He is also a Sr. Education Consultant at EMC Corp. He has also served as a Training Solutions Architect at NetApp, where he managed the engineering on-boarding and training curricula development. Prior to NetApp, he was Training Site Manager at Hitachi Data Systems Academy in charge of development and delivery of enterprise storage arrays certification programs. He also was the global network storage curricula manager at Hewlett-Packard. His areas of expertise are data center storage design and architecture, Data ONTAP, cloud storage, and virtualization. He has also held variety of positions at Cisco, Novell and SCO as a consultant and escalation engineer. He implemented the first university-level Data Storage and Virtualization curriculum in Northern California back in 2007. SNIA is a proud sponsor of the Storage Visions Conference, a partner program of the Consumer Electronics Show (CES).  Storage Visions, held in Las Vegas right before CES on January 3-5, 2016, is the place to explore the latest information on the rapidly evolving technology of digital storage and how it impacts consumer electronics, the internet of things, and storage in the cloud. If you have not registered for Storage Visions, head over to http://www.storagevisions.com for the conference preview.  Take $100 off your registration with the link:  https://sv2016.eventbrite.com/?discount=onehundredoff_67349921

by Marty Foltyn SNIA on Storage continues its preview of SNIA Tutorials at the Storage Visions Conference. SNIA is a proud sponsor of the Storage Visions Conference, a partner program of the Consumer Electronics Show (CES).  Storage Visions, held in Las Vegas right before CES on January 3-5, 2016, is the place to explore the latest information on the rapidly evolving technology of digital storage and how it impacts consumer electronics, the internet of things, and storage in the cloud. If you have not registered for Storage Visions, head over to http://www.storagevisions.com for the conference preview.  Take $100 off your registration with the link:  https://sv2016.eventbrite.com/?discount=onehundredoff_67349921 "SNIA Education Day" is held on the afternoon of the pre-conference day at Storage Visions - January 3, 2016 - and is designed to give attendees the opportunity to learn about important storage topics on depth with leading industry speakers. In the SNIA on Storage December 17th blog, we featured a tutorial which examines the conflict between privacy and data protection as illustrated in the European Union, but really applicable worldwide. In the December 18 blog, we previewed the Practical Online Cache Analysis and Optimization tutorial. Today's blog highlights a topic of key interest to those building Internet of Things (IoT) applications - Massively Scalable File Storage which will be presented by Philippe Nicholas on SNIA Education Day at Storage Visions. The Internet has changed the world and continues to revolutionize how people are connected, exchange data, and do business. This radical change is one of the causes of the rapid explosion of data volume that required a new data storage approach and design. One of the common elements is that unstructured data rules the IT world. How can famous Internet services we all use everyday support and scale with thousands of new users added daily and continue to deliver an enterprise-class SLA? What are the various technologies behind a Cloud Storage service to support hundreds of millions of users? This tutorial covers technologies introduced by famous papers about Google File System and BigTable, Amazon Dynamo, and Apache Hadoop. In addition, Parallel, Scale-out, Distributed, and P2P approaches with Lustre, PVFS, and pNFS with several proprietary ones are presented. This tutorial also discusses some key features such as erasure coding which are essential at this large scale to help understand and differentiate industry vendor offerings. Tutorial presenter Philippe Nicolas is a recognized storage industry expert with more than 20 years of experience. He is currently an advisor for companies including Rozo Systems, Guardtime, and Solix Technologies. Philippe drove the Industry Strategy at Scality after leading the Product Strategy since 2011. He was at Brocade for 2 years as technology evangelist and strategist and spent nearly 10 years at Veritas Software and Symantec in different technology and product roles. Philippe started the SNIA Europe France regional committee in 2001, and served as Chairman for France until February 2010. He served twice on the SNIA Europe Board of Directors and was a founder of the SNIA Cloud Storage Initiative. He is the author of four SNIA Tutorials on Data Sharing, File Storage, Massive Scalability, and Cloud Storage. In 2005, Philippe received the Outstanding Service Award from the SNIA Europe for his industry and association contribution. He holds an engineering degree in computer sciences from ESI.

by Marty Foltyn SNIA on Storage continues its preview of SNIA Tutorials at the Storage Visions Conference. "SNIA Education Day" is held on the afternoon of the pre-conference day at Storage Visions - January 3, 2016 - and is designed to give attendees the opportunity to learn about important storage topics on depth with leading industry speakers. SNIA will exhibit at Storage Visions January 4-5, 2016 in booths 204-208, featuring the latest on Solid State Storage and certification activities. If you have not registered for Storage Visions, head over to http://www.storagevisions.com for the conference preview and registration. In December 17th SNIA on Storage blog, we reviewed a tutorial which examines the conflict between privacy and data protection as illustrated in the European Union, but really applicable worldwide. Today, we take a look at a SNIA Tutorial #2 in the SNIA Education Day Agenda - Practical Online Cache Analysis and Optimization. This tutorial will take a technical dive into how to analyze and optimize high-performance storage caches using lightweight, continuously-updated miss ratio curves (MRCs). The benefits of storage caches have been notoriously difficult to model and control, varying widely by workload, and exhibiting complex, nonlinear behaviors. Now, however, MRCs (previously relegated to offline modeling), can be computed so inexpensively that they are practical for dynamic, online cache management, even in the most demanding environments. The tutorial will examine new opportunities afforded by MRCs to capture valuable information about locality that can be leveraged to guide efficient cache sizing, allocation, and partitioning, in order to support diverse goals such as improving performance, isolation, and quality of service. The presenters will also describhow multiple MRCs can be used to track different alternatives at various timescales, enabling online tuning of cache parameters and policies. Tutorial presenter Carl Waldspurger has been leading research at CloudPhysics since its inception. He is active in the systems research community, and serves as a technical advisor to several startups. For over a decade, Carl was responsible for core resource management and virtualization technologies at VMware. Prior to VMware, he was a researcher at the DEC Systems Research Center. Carl holds a PhD in computer science from MIT. Co-presenting with Carl is Irfan Ahmad, Chief Technology Officer of CloudPhysics which he cofounded in 2011. Prior to CloudPhysics, Irfan was at VMware, where he was R&D tech lead and co-inventor for flagship products. Irfan has worked extensively on interdisciplinary endeavors in memory, storage, CPU, and distributed resource management, and has developed a special interest in research at the intersection of systems. SNIA is a proud sponsor of the Storage Visions Conference, a partner program of the Consumer Electronics Show (CES).  Storage Visions, held in Las Vegas right before CES on January 4-5, 2016, is the place to explore the latest information on the rapidly evolving technology of digital storage and how it impacts consumer electronics, the internet of things, and storage in the cloud.

SNIA is a proud sponsor of the Storage Visions Conference, a partner program of the Consumer Electronics Show (CES).  Storage Visions, held in Las Vegas right before CES on January 3-5, 2016, is the place to explore the latest information on the rapidly evolving technology of digital storage and how it impacts consumer electronics, the internet of things, and storage in the cloud. SNIA will exhibit at Storage Visions on booths 204-208, featuring  the latest on Solid State Storage,  and certification activities. Over the next week, the SNIA on Storage blog will highlight the sessions in SNIA Education Day, a pre-conference event on January 3, 2016 that gives Storage Visions attendees vendor-neutral technical education on key storage issues.  If you have not registered for Storage Visions, head over to http://www.storagevisions.com for the conference preview and registration. SNIA Tutorial Privacy vs. Data Protection examines the impact of European Union data protection legislation. Attendees will learn how, after reviewing the diverging data protection legislation in the EU member states, the European Commission (EC) decided that this situation would impede the free flow of data within the EU zone.  The EC response was to undertake an effort to harmonize the data protection regulations and it started the process by proposing a new data protection framework.  The tutorial will discuss the impacts of this proposal on data handling practices, as it includes some significant changes like defining a data breach to include data destruction, adding the right to be forgotten, adopting the U.S. practice of breach notifications, and many other new elements.  Another major change is a shift from a directive to a rule which means the protections are the same for all 28 countries and includes significant financial penalties for infractions. Tutorial presenter Thomas Rivera has over 29 years of experience in the storage industry, specializing in file services and data protection, and is a Senior Technology Associate with Hitachi Data Systems (HDS). Thomas is an active member of the Storage Networking Industry Association (SNIA), serving as secretary of the SNIA Board of Directors, participating as co-chair of the Data Protection & Capacity Optimization (DPCO) Committee, and is also a member of the Analytics & Big Data Committee, as well as the Storage Security Technical Working Group (TWG). SNIA Tutorials are an important element of the SNIA Education continuum of Certification, Curriculum, and Tutorials.   SNIA Tutorials are educational materials developed by vendors, training companies, analysts, consultants, and end-users in the storage networking industry.  They are intended to present technical and business issues covering Information Technology in a fair and unbiased manner, and designed to give a consensus view of particular topics, from the viewpoint of the entire industry or a significant segment.  View the entire array of SNIA Education at http://www.snia.org/education.

Our recent Ethernet Storage Forum Webcast, “Storage Performance Benchmarking: Part 2,” has already been viewed by more than 500 people. If you haven’t seen it yet, it’s now available on –demand. Our expert presenters, Ken Cantrell and Mark Rogov did a great job fielding questions during the live event, but of course there wasn’t time to get to them all. So, as promised here are their answers to all of them. If you have additional questions or thoughts, please comment on this blog and we’ll get back to you as soon as we can.

Q: “As an example, am I right to presume workloads are generated by VMs”

A: Ken: It is probably a good idea at this point to define a workload, since we continue to use the term. At a very high level, think of a workload as the mix of operations issued by an application related to the accessing of data. In our case, data stored or made available by a storage solution. With that in mind, absolutely, workloads can be generated by VMs. But they don’t have to be. In other words, “it depends.”

For example, consider these 3 cases:

1) If your SUT (solution under test) was just a simple laptop with no hypervisor and a traditional OS, then there would be no VM in the mix. Your workload would be generated by the application you were measuring (whether that was a simple file copy or something complex like a local database installation).

2) Your SUT is composed of a physical client (like the laptop above) attached to a machine with a hypervisor installed on it and a local guest OS installation that is capable of exporting NFS or SMB shares. The laptop sends I/O via Ethernet to the guest OS. In this example, there is a VM, but it is acting as the storage system, not the workload generator.

3) Now reverse the I/O of example 2. Have the laptop export an SMB share and have the guest OS issue I/Os to that share. Now you finally have VMs generating workloads.

A: Mark: If one examines the solution under test (SUT), and considers the general data flow, then the workload is generated by the clients/hosts layer. Yes, we indicated that the clients/hosts can be VMs, but they also could be physical systems, and, in the case of a SUT consisting of just one laptop, the workload is generated by the application.

Q: Are you going to get around to file performance benchmarking? This infrastructure stuff is not new to me. I have done block all my life, I am interested in stuff about file.

A: Ken: That’s the plan. We are still working out the exact sequence, timing and content for future presentations, but had a dedicated section on both block and file on the original roadmap. If you have specific topics within “file” that you’d like covered, respond in the comments. No promises to cover them, but knowing the desires of the audience is always a good thing.

Keep in mind the intention of the webcast series – lay a strong, but simple foundation, for storage performance fundamentals and then build on that foundation.

A: Mark: The main intent of the series is to lay down basic performance principles first, then build on them to go to more complex topics. Both Ken and I refer to ourselves as “File Heads” and we can’t wait to concentrate on just file, but it would only make sense given that the infrastructure foundations are firm and understood by our audience.

Q: Why doesn’t SPEC SFS have performance testing for such failure models?

A: Ken: Brighttalk provided this comment in isolation, so it isn’t entirely clear which failure models you’re asking for.  I’m assuming you mean a failure like a drive or controller failure. With that assumption, that said, the SFS subcommittee welcomes publications that illustrate a failure condition. SPEC SFS 2014 provides an excellent opportunity for someone to publish once in a non-failure scenario and then again in a failure condition of some sort – as long as that failure condition doesn’t violate any of the run rules regarding stable storage and the failure condition doesn’t generate user visible errors.

Note that SPEC SFS 2014 doesn’t mandate any demonstration of failure scenarios. We’ve discussed this in the past, but it has never been a priority for those that participate in SPEC (which is open to all – see http://www.spec.org for instructions on how to join the SPEC Open Systems Group).

Q: Why is write cache turned off for enterprise drives?

A: Ken: I knew this question was coming. This is related to “stable storage” – the guarantee from your storage provider that data they say is safely stored on disk is actually stored on disk. I should clarify that the comment is a little dated and refers to caches designed around volatile memory; this wouldn’t apply to a hybrid SSD/spinning media drive that used the SSD to cache/stage data, since SSDs are non-volatile.

Consider the failure scenario where the enterprise drive has write caching enabled and then experiences a power failure. In most every system sold, the storage controller treats drives pretty much as black boxes – they tell the drive to read or write data at a certain location and expect the drive to do as told. So, when the drive says “yup, I got that data, you’re good!” the storage solution trusts the drive and, when it doesn’t need it in memory any longer, throws it away (that data is safely stored on disk, so this is ok). If the drive chose to cache that information in volatile memory, and loses power, the information is gone.

Midrange and enterprise storage vendors often (I think I can say generally) provide some sort of battery backup in case of power failures. These battery units keep power to at least some of the drives – but remember that drives (especially spinning ones) suck down a lot of power, and often the implementation chooses to keep power only to certain drives that the storage controller uses to flush its own volatile memory structures to.

A quick Internet search shows some specific comments on this topic:

From Seagate (http://knowledge.seagate.com/articles/en_US/FAQ/187751en):

Windows 2000 Professional / Server, Windows XP Home / Professional, Windows Vista and Windows 7 have a nifty little feature called write caching buried within the depths of property tabs. Normally, this type of feature is used with SCSI drives in server applications to provide greater data integrity.

When drives employ write-back cache, any interruption of power to the drive or system may cause lost or corrupted data because the drive does not have time to write the cached data to the disk before the power is lost. However, when write cache is turned off, drive performance slows down.

From Microsoft (https://support.microsoft.com/en-us/kb/259716):

…In addition, enabling disk write caching may increase operating system performance. This article describes how to enable or disable disk write caching…

NOTE: Enabling write caching generates the following warning. This is normal:

By enabling write caching, file system corruption and/or data loss could occur if the machine experiences a power, device or system failure and cannot be shutdown properly.

Q: What’s the difference between CPU and ASIC? When to use which word?

A: Ken: Unfortunately, the SNIA dictionary doesn’t define either term. At the easiest level, both are acronyms. CPU = central processing unit, and ASIC = application specific integrated circuit. At the next level, think of a CPU as general purpose processing element and an ASIC as a custom designed microchip designed for a special application or purpose. Once created, ASICs are non-programmable – they do something very specific (and hopefully very well and very quickly/efficiently). A CPU can run your bitcoin mining program overnight, wake you to Spotify in the morning, let you use your favorite word processor in between games of Plants vs. Zombies, and still let you watch Hulu before you head off to bed.

An ASIP (Application Specific Instruction-Set Processor) bridges the gap between a general purpose processor (CPU) and the highly specific, targeted design of an ASIC. An ASIP will have a much reduced instruction set and a more targeted design towards a specific application (say, digital signal processing), but still allow the execution of a specific instruction set given to it.

Q: Can you mention tools to identify the bottlenecks?

A: Ken: We are trying very hard, particularly in the webcasts themselves, to stay vendor neutral. I don’t mind violating that though here in the Q&A a little bit.

From an open source standpoint, there are a number of tools. One of the more popular now is to use something like Graphana as a front-end to Graphite, and use that to monitor a set of open source (or privately designed) sensors, including sensors from OPM below, that you place throughout your environment.

Here are a few other open-source benchmarking and performance tools, and what aspect of performance to which they apply. Please note that this is not a comprehensive list, nor is this a recommendation for their use. We are providing the link as a convenience, not an endorsement. [http://www.opensourcetesting.org/performance.php]

Still free, but NetApp-centric, is OnCommand Performance Manager (OPM), specifically OPM v2.0 and later. In addition to providing performance metrics for your NetApp storage array, OPM offers up the concept of a “bully” and “victim” scenario – it specifically watches for components that are performing poorly (the “victims”) and helps identify which other components are causing that poor behavior (the “bullies”). My team helps develop OPM.

Not free, and not NetApp centric, but a NetApp product, is OnCommand Insight (OCI). This is a premier product for looking at the performance of the components across your datacenter.

A: Mark: I didn’t want to break the vouch to neutrality. EMC has a number of tools as well, vRealize suite, ViPR SRM, Unisphere, plus platform specific tools… However, it has been my experience that the most important tool a performance expert has is still the critical mind. One observes the problem, and then walks the entire set of the SUT layers looking for incongruences. Too often, the perceived bottleneck is not the problem, but a manifestation of a problem somewhere else. For example, as we pointed in the “MiB/s section” of this webcast, the network layer was a bottleneck due to the badly configured OS multipath drivers. Deciphering cause from reason requires several things: a good understanding of the SUT and its layers; a critical mind to analyze problem conditions; and a large dose of curiosity. The latter one a personal trait that drives us to question “what if I change this to that?” Asking questions while troubleshooting is, IMHO, a cornerstone requirement and inherently, a very human trait. My personal view is that tools are just tools, and they require a human hand to operate and a human mind to analyze the results.

Q: Did All flash arrays almost eliminate bottleneck..,at least the Storage controller bottleneck can be eliminated if enterprise can afford all flash arrays?

A: Ken: Actually, almost exactly the opposite. Spinning drives are (now, at least) relatively slow. Over the past 10 years the drives have gotten much bigger, although HDD drive speeds haven’t really changed all that much,. Because of this, what I’ve observed is that the IOPS/GB ratio for HDD has, if anything, been getting worse* and the most common bottleneck for an HDD-based customer turns out to be the speed of their drives.

Now consider what happens when a customer moves to SSDs. The SSDs that are sold (and folks can afford) are generally much smaller than the HDDs they are used to, so customers buy as many of them as they can in order to meet their capacity requirements. And the SSDs are, one-for-one, much faster. So what happens? High drive counts + really fast drives = the drives aren’t your bottleneck anymore. Instead, the bottleneck shifts upstream … in a well architected solution, generally to the storage controller or clients.

*For those that know the terms, we could have a long discussion about working set sizes over the years, how fast data ages, tiered storage and such, and the effect that these have on observed iops/GB … but I think we could agree that since HDD speeds aren’t increasing, the iops/GB ratio isn’t generally getting better.

Q: Can I download this slides?

A: Ken: Absolutely. Here are the links to Part 1 of our series:

PPT and PDF: http://www.snia.org/forums/esf/knowledge/webcasts (look for “Storage Performance Benchmarking: Introduction and Fundamentals (July 2015)”)

Presentation Recording: https://www.brighttalk.com/webcast/663/164323

Q&A Blog: http://sniaesfblog.org/?p=447

Here are the links to Part 2:

PPT and PDF: http://www.snia.org/forums/esf/knowledge/webcasts (look for “Storage Performance Benchmarking: Part 2 (October 2015)”)

Presentation Recording: https://www.brighttalk.com/webcast/663/164335

Q&A Blog: That’s what you’re reading now.

Q: Storage controller, is a compute node, right? And for hyper converged systems, storage controller and compute nodes are the same, right?

A: Mark: Most certainly, a Storage Controller can be a compute node, but in our webcast it is not. The term “compute node” is typically interpreted to be a part of the client/hosts layer. A compute node computes for the application, and such application is generating the workload (please see the question above about where workload is initiated).

A good example of the compute node would be a system that renders cartoons, or geodesic fields. As such compute node computes something (application does the work), and stores the results onto the storage controller.

However, in the case of hyper-converged infrastructure, the storage controller is often virtualized among the client hosts, making every compute node a part of a larger storage controller.

Q: Are the performance numbers that vendors publish typically front-end?

A: Mark: I don’t want to generalize published numbers as being one way or another. I recommend reading every publication for specific details. Vendors publish numbers to cover use cases, and each use case may come with its own set of expected measurement points and metrics. Ken and I talked about how metrics matter in the first Storage Performance Benchmarking webcast.

Q: “We did an R&D PoC using 32 flash 400GB elements attached on DIMM slots (not through SAS controller, not a direct PCIe attach) and seven 40Gbps cards. We were able to pump 5.5M 4KB-IOPS resulting in 30GB/s (240Gbps) of traffic on the front-end connect. When do you expect the front-end connect be the bottleneck for more standard environment?”

A: Ken: Woot! That sounds like a lot of fun. If you’re in the Raleigh, NC area and can talk about that not under NDA, we should have lunch. I’d like to hear more.

I have a suspicion that this answer won’t satisfy you, because it isn’t going to be as empirical as your example. The problem in answering with raw numbers is that there isn’t a standard configuration for a SUT. An enterprise class storage array with a mix of 40GbE and 32GB FC connections (with traffic over both) will look very different than someone using their old Windows XP box with a single 100Mbit to share out an SMB share, and both will look different than someone accessing their photos on their favorite cloud provider. So, I’ll answer the question by saying that I expect the front-end connect to be the bottleneck anytime the rest of the components in the SUT are capable of hitting your performance metrics (whether that be in terms of response time, IOPS, or data rates), and the front-end connect isn’t.

THAT said, you’d be astounded how often, even today, that MTU mismatches result in terrible front-end performance (and functionality).

Q: “Example of cache in front end connection?”

A: Ken: I’ll cheat and note that SUTs can be a lot more complicated than we showed. For example, our picture looked like this:

 

Consider a SUT then where you have:

At one level, “the internet” is just a big black box acting as our front-end connect. But if we zoom in on it, perhaps we find that somewhere along the line there’s a caching server. Then we have an easy answer to where you find cache in the front-end connect.

In the much simpler model that you’ll find in many enterprise data environments though, you’ll find that the front-end connect consists of some relatively short length cables and a set of switches – either SAN or NAS switches. And in those environments, you won’t find a lot of cache. You will find memory, but you’ll find it used for buffering more than for caching.

We tried to minimize this in the presentation since there’s not a universally agreed upon distinction between these two terms. I think of a buffer (in this context) primarily as memory set aside to hold data very briefly, after which it is consumed and removed from the buffer. I think of cache, on the other hand, as a storage medium that holds data specifically to speed up data access (storage or retrieval). Data held in a cache can be held for a very long time, and not all data in a cache may ever be consumed/used.

Q: Even SSDs suck at random write but they are good for random read, is there that much difference?

A: Ken: Yes. The data we pulled for drive speeds was real data. And keep in mind that “sucks” is pretty relative here. Enterprise SSDs still tend to be at least 4x faster than spinning media. And, very importantly, their performance is much more consistent and deterministic since seek time is irrelevant with an SSD. New NVRAM technologies, like 3D XPoint, promise to dramatically improve write performance.

DRAM is volatile though so replacing HDDs with that wouldn’t really work, right? But if capacity requirements are high, we cannot replace disks with the cache, right?

A: Mark: Cache should never replace capacity. Cache is temporary storage, and requires by design to move its data to a permanent storage location. The size of cache should be matched to the size of the data that application uses, so called “working area”. For example, if an application writes to a 4GB file (think VMware vmdk), then for best performance the entire 4GB should fit into cache. However, capacity requirements for a VMware datastore can be as high as several TB. If the application (ESX server) is running many VMs, perhaps only the performance few need to fit into cache, while all other VMs would use cache for sub-portions of their vmdks.

A: Ken: You’re right, not permanently. As Mark points out, it isn’t to permanently replace the slower storage with cache necessarily, just supplement it enough that the working set fits in.

Q: How can we make client do less IO? Will it make sense?

A: Mark: A client does less IO by using larger IO size, for example. A classic use case is read- and write-sizes within NFS protocol. It is possible to increase read- and write-size of the NFS protocol from the NFS client mount options side. By default, some Linux environments use 32KB for reads and writes. And reading a 1GB file takes 32768 32KB IOs. If the read size is increased to 1GB, then it takes only 1024 IOs – a 32x reduction!

A: Ken: Other options involve app re-writes (yes, sometimes these ARE possible) and OS upgrades. Perhaps in the “app-rewrite” category, or maybe a new category, I’ve also worked with developers to rewrite their DB queries to be much less disk intensive, for example.

Q: Can you elaborate on some of the client level cache types other than file system or OS?

A: Mark: Other than file system and OS? Hmm… Let’s see: PCI-based cards that cache block-device level cache, e.g. EMC VFCache, SanDisk Fusion-IO, NetApp Flash Cache. Native network protocols (CIFS and NFS) caches. Local database caching, e.g., SafePeak, TimesTen, Windows Azure Caching.

Q: Please add more sessions, which goes into every detail

A: Mark: Absolutely! We will! Promise! We’re shooting for Part 3 in Q1 2016.

The impact of international data protection legislation on the cloud is complicated and constantly changing. In our recent SNIA Cloud Storage Webcast on this topic we did our best to cover some of the recent global data privacy and data protection regulations being enacted. If you missed the Webcast, I encourage you to watch it on-demand at your convenience. We answered questions during the live event, but as promised we’re providing more complete answers in this blog. If you have additional questions, please comment here and we’ll reply as soon as we can.

The law is complex, and neither SNIA, the authors nor the presenters of this presentation are lawyers. Nothing here or in the presentation should be construed as legal advice. For that you need the services of a qualified professional.

Q. What are your thoughts on Safe Harbour being considered invalid, and the potential for a Safe Harbour 2

A. Since 6 October 2015 when the European Court of Justice invalidated the European Commission’s Safe Harbour Decision, there’s been a lot written about Safe Harbour 2 in the press. But it was clear that a renegotiation was essential two years before that, when discussions for a replacement were started. Many think (and many hope!) that a new and valid agreement in terms of Europe’s Human Rights legislation will be settled between the US and Europe sometime in March 2016.

Q. Are EU Model Clauses still available to use instead of BCRs (Binding Corporate Rules)?

A. EU-US data transfers facilitated by the use of model clauses probably today fail to comply with EU law. But as there appears to be no substitute available, the advice appears to be – use them for now until the problem is fixed. Full guidance can be found on the EC website.

Q. What does imbalance mean relative to consent?

A. An example might help. You might be an employee and agree (the “consent”) to your data being used by your employer in ways that you might not have agreed to normally – perhaps because you feel you can’t refuse because you might lose your job or a promotion for example. That’s an imbalanced relationship, and the consent needs to be seen in that light, and the employer needs to demonstrate that there has been, and will be, no coercion to give consent.

by Marty Foltyn The Consumer Electronics Show (CES), held each year in early January in Las Vegas, has moved a long way from the days when you had to search high and low on the show floor for storage-related exhibits. Step on the floor in 2016, and you may never get past the automobile displays which have the capability to track and store your every activity. And even if you do, the plethora of accessible tech, video imaging, and smart home apps will make your head spin! Solid State Storage is an important contributor to the internet of things featured at CES, and understanding it is key to making informed choices. Get ready for CES 2016 by first attending a SNIA Solid State Storage webcast on Friday, December 11 at 11:00 am Pacific where Tom Coughlin, CEO of analyst firm Coughlin Associates, presents Flash Memory Enables 4K and Beyond Video Workflows. As the price and availability of flash memory grows flash memory will enable future generations of media that is even more immersive than today as video moves to 8K and virtual reality begins to play an increasing role in entertainment. Tom will discuss how, as the resolution and frame rate for video increase, flash memory is staring to play a significant role for content capture, post production and content delivery. His presentation will include material from the 2015 Digital Storage in Media and Entertainment Report from Coughlin Associates (and the associated 2015 digital media professional survey) on the growing use of flash memory in all aspects of professional media and entertainment and put flash use in context with other storage technologies in this industry. The webcast is an important lead in to the CES partner program Storage Visions Conference January 3-4 in Las Vegas, where SNIA will exhibit  solid state and persistent memory and have a pre-conference education day.  Register for this informative SNIA Brighttalk webcast , held on December 11, 2015 at 11:00 apm Pacific/2:00 pm Eastern at https://www.brighttalk.com/webcast/663/180197

by Marty Foltyn

The Consumer Electronics Show (CES), held each year in early January in Las Vegas, has moved a long way from the days when you had to search high and low on the show floor for storage-related exhibits. Step on the floor in 2016, and you may never get past the automobile displays which have the capability to track and store your every activity. And even if you do, the plethora of accessible tech, video imaging, and smart home apps will make your head spin!

Solid State Storage is an important contributor to the internet of things featured at CES, and understanding it is key to making informed choices. Get ready for CES 2016 by first attending a SNIA Solid State Storage webcast on Friday, December 11 at 11:00 am Pacific where Tom Coughlin, CEO of analyst firm Coughlin Associates, presents Flash Memory Enables 4K and Beyond Video Workflows.

As the price and availability of flash memory grows flash memory will enable future generations of media that is even more immersive than today as video moves to 8K and virtual reality begins to play an increasing role in entertainment. Tom will discuss how, as the resolution and frame rate for video increase, flash memory is staring to play a significant role for content capture, post production and content delivery. His presentation will include material from the 2015 Digital Storage in Media and Entertainment Report from Coughlin Associates (and the associated 2015 digital media professional survey) on the growing use of flash memory in all aspects of professional media and entertainment and put flash use in context with other storage technologies in this industry.

The webcast is an important lead in to the CES partner program Storage Visions Conference January 3-4 in Las Vegas, where SNIA will exhibit  solid state and persistent memory and have a pre-conference education day.  Register for this informative SNIA Brighttalk webcast , held on December 11, 2015 at 11:00 apm Pacific/2:00 pm Eastern at https://www.brighttalk.com/webcast/663/180197