The SNIA Solid State Storage Initiative would like to thank everyone who attended our webcast: How To Be Part of the Real World Workload Revolution.  If you haven’t seen it yet, you can view the on demand version here.  You can find the slides here. Eden Kim and Jim Fister led a discussion on the testmyworkload (TMW) tool and data repository, discussing how a collection of real-world workload data captures can revolutionize design and configuration of hardware, software and systems for the industry.   A new SNIA white paper available in both English and Chinese authored by Eden Kim, with an introduction by Tom Coughlin of Coughlin Associates and Jim Handy of Objective Analysis, discusses how we can all benefit by sharing traces of our digital workloads through the SNIA SSSI Real-World Workload Capture program. In an environment where workloads are becoming more complex — and the choices of hardware configuration for solid-state storage are growing — the opportunity to better understand the characteristics of data transfers to and from the storage systems is critical.  By sharing real-world workloads on the Test My Workload repository, the industry can benefit overall in design and development at every level from SSD development to system configuration in the datacenter. There were several questions asked in and after the webcast.  Here are some of the answers.  Any additional questions can be addressed to asksssi@snia.org. Q: Shouldn’t real world workloads have concurrent applications?  Also, wouldn’t any SQL workloads also log or journal sequential writes? A: Yes.  Each capture shows all of the IO Streams that are being applied to each logical storage recognized by the OS.  These IO Streams are comprised of IOs generated by System activities as well as a variety of drivers, applications and OS activities.  The IOProfiler toolset allows you to not only see all of the IO Stream activity that occurs during a capture, but also allows you to parse, or filter, the capture to see just the IO Streams (and other metrics) that are of interest. Q: Is there any collaboration with the SNIA IOTTA Technical Work Group on workload or trace uploading? A:  While IOTTA TWG and SSS TWG work closely together, an IO Capture is fundamentally different from an IO Trace and hence is not able to be presented on the IOTTA trace repository.  An IO Trace collects all of the data streams that occur during the IO Trace capture period and results in a very large file.  An IO Capture, on the other hand, captures statistics on the observed IO Streams and saves these statistics to a table.  Hence, no actual personal or user data is captured in an IO Capture, only the statistics on the IO Streams. Because IO Captures are a series of record tables for individual time steps, the format is not compatible with a repository for the streaming data captured in an IO Trace. For example, an IO Trace could do a capture where 50,000 RND 4K Write and 50,000 RND 4K Read IOPS are recorded, resulting in 100,000 4K transfers, or 40M bytes of data.  OTOH, an IO Capture that collects statistics would log the fact that 50,000 RND 4K Writes and 50,000 RND 4K Reads occurred… a simple two item entry in a table.  Of course, the IOPS, Response Times, Queue Depths and LBA Ranges could also be tracked resulting in a table of 100,000 entries times the above 4 metrics, but 400,000 table entries is much smaller than 40 MB of data. Both of these activities are useful, and the SNIA supports both. Q: Can the traces capture a cluster workload or just single server? A: IO Captures capture the IO Streams that are observed going from User space to all logical storage recognized by the OS.  Accordingly, for clusters, there will be an individual capture for each logical unit.  Note that all logical device captures can be aggregated into a single capture for analysis with the advanced analytics offered by the commercial IOProfiler tools. Q: Have you seen situation where the IO size on the wire does not matched what application request?  Example Application request 256K but driver chopped the IO into multiple 16K before sent to the storage. How would we verify this type of issue? A: Yes, this is a common situation. Applications may generate a large block SEQ IO Stream for video on demand.  However, that large block SEQ IO Stream is often fragmented into concurrent RND block sizes.  For example, in Linux OS, a 1MB file is often fragmented into random concurrent 128K block sizes for transmission to and from storage, but then coalesced back into a single 1024K BS in user space.. Q: Will you be sharing the costs for your tools or systems? A: The tool demonstrated in the webcast is available free at testmyworkload.com (TMW).  This is done to build the repository of workloads at the TMW site.  Calypso Systems does have a set of Pro tools built around the TMW application.  Contact Calypso for specific details. Q: Can the capture be replayed on different drives? A: Yes.  In fact, this is one of the reasons that the tool was created.  The tool and repository of workloads are intended to be used as a way to compare drive and system performance, as well as tune software for real-world conditions. Q: How are you tracking compressibility & duplication if the user does not turn on compression or dedupe? A: The user must turn on compression or duplication at the beginning of the capture to see these metrics. Q: An end user can readily use this to see what their real world workload looks like.  But, how could an SSD vendor mimic the real world workload or get a more “realworld-like” workload for use in common benchmarking tools like FIO & Sysbench? A: The benchmarking tools mentioned are synthetic workloads, and write a predictable stream to and from the drive.  IO Captures ideally are run as a replay test that recreates the sequence of changing IO Stream combinations and Queue Depths observed during the capture.  While the Calypso toolset can do this automatically, free benchmark tools like FIO and sysbench may not be able to change QDs and IO Stream combinations from step to step in a test script.  However, the IO Capture will also provide a cumulative workload that list the dominant IO Streams and their percentage of occurrence.  This list of dominant IO Streams can be used with fio or sysbench to create a synthetic composite IO stream workload. Q: Is it possible to use the tool to track CPU State such as IOWAIT or AWAIT based on the various streams? A: Yes, IO Captures contain statistics on CPU usage such as CPU System Usage %, CPU IO Wait, CPU User usage, etc. Q: Can we get more explanation of demand intensity and comparison to queue depth? A: Demand Intensity (DI) is used to refer to the outstanding IOs at a given level of the software/hardware stack.  It may be referred to simply as the outstanding Queue Depth (QD) or as the number of outstanding Thread Count (TC) and QD.  The relevance of TC depends on where in the stack you are measuring the DI.  User QD varies from level to level and depends on what each layer of abstraction is doing.  Usually, focus is paid to the IO Scheduler and the total outstanding IOs at the block IO level.  Regardless of nomenclature, it is important to understand the DI as your workload traverses the IO Stack and to be able to minimize bottlenecks due to high DI. Q: In these RWSW application traces do these include non-media command percentages such as identify and read log page (SMART), sleep states, etc.?  Depending on the storage interface and firmware this can adversely affect performance/QoS. A: IO Capture metrics are the IO Streams at the logical storage level and thus do not include protocol level commands.  Non performance IO commands such as TRIMs can be recorded, and SMART logs can be tracked if access to the physical storage is provided. Q: Isn’t latency a key performance metric for these workloads so collecting only 2 minute burst might not show latency anomalies? A: IO Captures average the statistics over a selected time window.  Each individual IO Stream and its metrics are recorded and tabulated on a table but the time window average is what is displayed on the IO Stream map.  Of course, the min and max Response times over the 2 minute window are displayed, but the individual IO latencies are not displayed.  In order to track IO Bursts, the time window resolution should be set to a narrow time range, such as 100 mS or less, in order to distinguish IO Bursts and Host Idle times.

Video streaming is an easy-to-understand workload from the I/O perspective, right?  It’s pretty obvious that it’s a workload heavy on long, streaming reads. The application can be modeled with a consistent read flow, and the software tests should be easy.  However, an analysis of the real-world workload shows something very different. At the disk level, the reads turn out to be a rapid flow of 4k and 8k block reads from a solid-state-disk.  Further, other processes on the system also add in a small amount of 4k and 8k writes in the midst of the reads. All of this impacts the application –and an SSD — which was likely heavily tested on the basis of long, streaming reads.

Understanding the real-world characteristics of a workload can be a significant advantage in the development of new hardware, new systems, and new applications.   The SNIA Solid State Storage Initiative (SSSI) and SSSI member company Calypso Systems are providing an opportunity to build a repository of workloads for the industry to use for real-world testing, as outlined in a new SSSI white paper How to Be a Part of the Real-World Workload Revolution. This paper is also available in Chinese at the SSSI Knowledge Center White Papers page.

By going to the TestMyWorkload site, anyone can participate by providing a trace capture of an I/O workload that can be used by others to develop better products. The capture itself traces the block transfers, but does not capture actual data.  Any workload replay would use representative blocks, so there are no concerns about data security or integrity from these captures.

The repository can be used by any participant to test hardware and software, and can help system vendors and users optimize configurations for the best performance based on real-world data.  By participating in this effort, organizations and individuals can provide insight and gain from the knowledge of all the contributors.

Follow these three steps to be a part of the revolution today!

1.  Read the white paper.

2.  Download the free capture tools at TestMyWorkload.com.

3. Mark your calendar and register HERE to learn more in the free SNIA webcast How to Be a Part of the Real-World Workload Revolution on July 9 at 11:00 am Pacific/2:00 pm Eastern.

Video streaming is an easy-to-understand workload from the I/O perspective, right?  It’s pretty obvious that it’s a workload heavy on long, streaming reads. The application can be modeled with a consistent read flow, and the software tests should be easy.  However, an analysis of the real-world workload shows something very different. At the disk level, the reads turn out to be a rapid flow of 4k and 8k block reads from a solid-state-disk.  Further, other processes on the system also add in a small amount of 4k and 8k writes in the midst of the reads. All of this impacts the application –and an SSD — which was likely heavily tested on the basis of long, streaming reads. Understanding the real-world characteristics of a workload can be a significant advantage in the development of new hardware, new systems, and new applications.   The SNIA Solid State Storage Initiative (SSSI) and SSSI member company Calypso Systems are providing an opportunity to build a repository of workloads for the industry to use for real-world testing, as outlined in a new SSSI white paper How to Be a Part of the Real-World Workload Revolution. By going to the TestMyWorkload site, anyone can participate by providing a trace capture of an I/O workload that can be used by others to develop better products. The capture itself traces the block transfers, but does not capture actual data.  Any workload replay would use representative blocks, so there are no concerns about data security or integrity from these captures. The repository can be used by any participant to test hardware and software, and can help system vendors and users optimize configurations for the best performance based on real-world data.  By participating in this effort, organizations and individuals can provide insight and gain from the knowledge of all the contributors. Follow these three steps to be a part of the revolution today! 1.  Read the white paper. 2.  Download the free capture tools at TestMyWorkload.com. 3. Mark your calendar and register HERE to learn more in the free SNIA webcast How to Be a Part of the Real-World Workload Revolution on July 9 at 11:00 am Pacific/2:00 pm Eastern.

It’s exciting to see the recent formation of the Solid State Drive Special Interest Group (SIG) here in the SNIA Solid State Storage Initiative.  After all, everyone appreciates the ability to totally geek out about the latest drive technology and software for file systems.  Right? Hey, where’s everyone going? We have vacation pictures with the dog we stored that we want to show…

Solid state storage has long found its place with those seeking greater performance in systems, especially where smaller or more random block/file transfers are prevalent.  Single-system opportunity with NVMe drives is broad, and pretty much unquestioned by those building systems for the modern IT environments. Cloud, likewise, has found use of the technology where single-node performance makes a broader deployment relevant.

There have been many efforts to build the case for solid state in networked storage.  Where storage and computation combine — for instance in a large map/reduce application — there’s been significant advantage, especially in the area of sustained data reads.  This has usually comes at a scalar cost, where additional systems are needed for capacity. Nonetheless, finding cases where non-volatile memory enhances infrastructure deployment for storage or analytics.  Yes, analytics is infrastructure these days, deal with it.

Seemingly independent of the hardware trends, the development of new file systems has provided significant innovation.  Notably, heavily parallel file systems have the ability to serve a variety of network users in specialized applications or appliances.  Much of the work has focused on development of the software or base technology rather than delivering a broader view of either performance or applicability.  Therefore, a paper such as this one on building a Lustre file system using NVMe drives is a welcome addition to the case for both solid state storage and revolutionary file systems that move from specific applications to more general availability.

The paper shows how to build a small (half-rack) cluster of storage to support the Lustre file system, and it also adds the Dell VFlex OS implemented as a software defined storage solution.  This has the potential to take an HPC-focused product like Lustre and drive a broader market availability for a high-performance solution. The combination of read/write performance, easy adoption to the broad enterprise, and relatively small footprint shows new promise for innovation.

The opportunity for widespread delivery of solid state storage using NVMe and software innovation in the storage space is ready to move the datacenter to new and more ambitious levels.  The SNIA 2019 Storage Developer Conference  is currently open for submissions from storage professionals willing to share knowledge and experience.  Innovative solutions such as this one are always welcome for consideration.

SNIA thanks and celebrates the many hardworking SNIA member volunteers whose technical work was awarded Best of Show at the recent Flash Memory Summit. SNIA won the FMS Most Innovative Flash Memory Technology Award, recognizing innovations that will change the way flash memory works and is used in products, for the SNIA Technical Position Real World Storage Workloads Performance Test Specification (RWSW PTS), developed by the SNIA Solid State Storage Technical Work Group (SSS TWG). “Real World Workloads are important for Data Center, IT, and Storage professionals,” said Eden Kim, Chair of the SSS TWG, and CEO of SNIA member company Calypso Systems “because real world workloads are very different from synthetic lab workloads and are key determinants in datacenter server and storage performance, optimization and qualification.”   Eden and Jennifer Dietz of SNIA member company Intel and Co-Chair of the SNIA Solid State Storage Initiative Marketing Committee accepted the award from Jay Kramer of Flash Memory Summit. SNIA also won the FMS Best of show Technology Innovation Award, recognizing that cloud and other large data centers typically prioritize their selection criteria for storage solutions as those that can achieve the highest possible performance while avoiding proprietary vendor lock-in.  SNIA and EXTEN HyperDynamic NVMe over Fabrics high-performance storage software were recognized for creating an open storage management specification that works with EXTEN storage software for being the first in the industry to provide a solution based on SNIA Swordfish and DMTF Redfish^® specifications. “We congratulate EXTEN Technologies for its innovation and well-deserved accolade,” said Don Deel, SNIA Storage Management Initiative Governing Board Chair. “By integrating SNIA Swordfish into its solution, EXTEN Technologies’ customers will benefit from a standards-based API that does not require learning the intricacies of storage infrastructure to handle day-to-day storage needs.” Accepting the award for SNIA at FMS were Mark Carlson of SNIA member company Toshiba Memory Systems and Bill Miller of SNIA member company Samsung Electronics, Co-Chairs of the SNIA Technical Council. Congratulations to all the SNIA volunteers who participated in the development of these award-winning specifications. SNIA Sessions at FMS Now Available for Viewing and Download Also at Flash Memory Summit, SNIA work and volunteers were on display in sessions on persistent memory (PM), solid state storage, form factors, and testing. A two-day PM track featured talks on advances in PM, PM hardware, PM software and applications, and remote persistent memory (PMEM-101-1; PMEM -102-1; PMEM-201-1; and PMEM-202-1). SNIA is now partnering with the Enterprise and Datacenter SSD Form Factor Working Group (EDSFF) on form factors and a Wednesday session outlined their advances (SSD-201-1). SNIA also presented a preconference seminar (G) on bringing your SSD testing up to date, and a SNIA Education afternoon with sessions on flash storage, programming and networking, buffers, queues, and caches; and a BoF on PM futures.  Check out all these sessions and more on the Flash Memory Summit proceedings page. SNIA Executive Director Michael Oros shared SNIA strategic directions and areas of focus in a FMS main stage presentation, available here. SNIA also presented updates on their work in Persistent Memory, Solid State Storage, and alliances at a well-attended reception on Monday evening.  The SSSI honored Doug Voigt, co-chair of the NVM Programming Technical Work Group, for his contributions to SNIA and the NVM Programming Model. We continued our discussions on the exhibit floor featuring JEDEC-compliant NVDIMM-Ns from SNIA Persistent Memory and NVDIMM SIG members AgigA Tech, Micron, Netlist, SMART Modular Technologies, and Viking in a Supermicro box running an open source performance demonstration.  If you missed it, the SIG will showcase a similar demonstration at the upcoming SNIA Storage Developer Conference September 24-27, 2018, and the SNIA Persistent Memory Summit January 24, 2019 at the Hyatt Santa Clara.  Register now for both events!

At our most recent webcast, "Everything You Wanted to Know About Storage But Were Too Proud To Ask: Part Turquoise - Where Does My Data Go?, our panel of experts dove into what really happens when you hit "save" and send your data off. It was an alphabet soup of acronyms as they explained the nuances of and the differences between:

• Volatile v Non-Volatile v Persistent Memory
• NVDIMM v RAM v DRAM v SLC v MLC v TLC v NAND v 3D NAND v Flash v SSDs v NVMe
• NVMe (the protocol)

As promised during the live event, here are answers to all the questions we received. Q. Is SRAM still used today? A. SRAM is still in use today as embedded CACHE (Level 1/2/3) within a CPU and very limited in external standalone packaging... This is due to cost and size/capacity. Q. Does 3D NAND use multiple voltage levels? Or does each layer use just two voltages? A. 3D NAND is much like Planar NAND in operation. Supporting all the versions (SLC, MLC, TLC, and future even QLC). Other challenges exist going vertical, but are unrelated to voltage levels being supported Q. How does Symbolic IO work with the NVDIMM-P? A. SNIA does not comment on individual companies. Please contact Symbolic IO directly. Q. When do you see NVMe over Fibre Channel becoming mainstream? Just a "guesstimate" A. At the time of this writing, FC-NVMe (the standardized form of NVMe over Fabrics using Fibre Channel) is in the final ratification phase and is technically stable. By the time you read this it will likely already be completed. The standard itself is already a mainstream form of NVMe-oF, and has been a part of the NVMe-oF standard since the beginning. Market usage for NVMe-oF will ramp up as vendors, products, and ecosystem developments continue to announce innovations. Different transport mechanisms solve different problems, and the uses for Fibre Channel are not 100% overlapped with Ethernet or Fibre Channel. Having said that, it would not be surprising that both FC and Ethernet-based NVMe-oF grew at a somewhat similar pace for the next couple of years. Q. How are networked NVMe SSDs addressed? A. Each NVMe-oF transport layer has an addressing scheme that is used for discovery. NVMe SSDs actually connect to the Fabric transport through a port connected with the NVMe controller. A thorough description of how this works can be found at the SNIA ESF webcast: "Under the Hood with NVMe over Fabrics." You can also check out the Q&A blog from that webcast. Q. NVMe has any specific connectors like SATA or SAS would do? A. When looking at the physical drive connector, the industry came up with an edge connector called "U.2" that supports NVMe, SAS and SATA drives. However, the backplane in the host system must be connected correctly Q. Other than a real-estate savings, what advantage does the 3D NAND offer?     Speed? A. 3D NAND brings to us the added space used for the floating gate. When we get down to 20nm and 16nm (the measured width of the that floating gate) it only allows a few electrons, yes actual electrons, to separate the states. With 3D NAND we have room grow the gate, allowing more electrons per level and gaining us the ability to have things like TLC and beyond a reality. Don't forget, you can check out the  recorded version  of the webcast at your convenience and you can  download the webcasts slides  as well if you'd like to follow along. Remember, this webcast was part of series. I encourage you to  register today  for our next one, which will be on September 28^, 2017 at 10:00 am PT – Part Cyan – Storage Management. And please visit the  SNIA ESF website  for our full library of ESF webcasts.      

At our most recent webcast, “Everything You Wanted to Know About Storage But Were Too Proud To Ask: Part Turquoise – Where Does My Data Go?, our panel of experts dove into what really happens when you hit “save” and send your data off. It was an alphabet soup of acronyms as they explained the nuances of and the differences between:

• Volatile v Non-Volatile v Persistent Memory
• NVDIMM v RAM v DRAM v SLC v MLC v TLC v NAND v 3D NAND v Flash v SSDs v NVMe
• NVMe (the protocol)

As promised during the live event, here are answers to all the questions we received. Q. Is SRAM still used today? A. SRAM is still in use today as embedded CACHE (Level 1/2/3) within a CPU and very limited in external standalone packaging… This is due to cost and size/capacity. Q. Does 3D NAND use multiple voltage levels? Or does each layer use just two voltages? A. 3D NAND is much like Planar NAND in operation. Supporting all the versions (SLC, MLC, TLC, and future even QLC). Other challenges exist going vertical, but are unrelated to voltage levels being supported Q. How does Symbolic IO work with the NVDIMM-P? A. SNIA does not comment on individual companies. Please contact Symbolic IO directly. Q. When do you see NVMe over Fibre Channel becoming mainstream? Just a “guesstimate” A. At the time of this writing, FC-NVMe (the standardized form of NVMe over Fabrics using Fibre Channel) is in the final ratification phase and is technically stable. By the time you read this it will likely already be completed. The standard itself is already a mainstream form of NVMe-oF, and has been a part of the NVMe-oF standard since the beginning. Market usage for NVMe-oF will ramp up as vendors, products, and ecosystem developments continue to announce innovations. Different transport mechanisms solve different problems, and the uses for Fibre Channel are not 100% overlapped with Ethernet or Fibre Channel. Having said that, it would not be surprising that both FC and Ethernet-based NVMe-oF grew at a somewhat similar pace for the next couple of years. Q. How are networked NVMe SSDs addressed? A. Each NVMe-oF transport layer has an addressing scheme that is used for discovery. NVMe SSDs actually connect to the Fabric transport through a port connected with the NVMe controller. A thorough description of how this works can be found at the SNIA ESF webcast: “Under the Hood with NVMe over Fabrics.” You can also check out the Q&A blog from that webcast. Q. NVMe has any specific connectors like SATA or SAS would do? A. When looking at the physical drive connector, the industry came up with an edge connector called “U.2” that supports NVMe, SAS and SATA drives. However, the backplane in the host system must be connected correctly Q. Other than a real-estate savings, what advantage does the 3D NAND offer?   Speed? A. 3D NAND brings to us the added space used for the floating gate. When we get down to 20nm and 16nm (the measured width of the that floating gate) it only allows a few electrons, yes actual electrons, to separate the states. With 3D NAND we have room grow the gate, allowing more electrons per level and gaining us the ability to have things like TLC and beyond a reality. Don’t forget, you can check out the recorded version of the webcast at your convenience and you can download the webcasts slides as well if you’d like to follow along. Remember, this webcast was part of series. I encourage you to register today for our next one, which will be on September 28^, 2017 at 10:00 am PT – Part Cyan – Storage Management. And please visit the SNIA ESF website for our full library of ESF webcasts.      

In Part Vermillion of our SNIA Ethernet Storage Forum (ESF) “Everything You Wanted To Know About Storage But Were Too Proud To Ask” webcast series – we examined the terms and concepts are at the heart of where compute, networking and storage intersect. That’s why we called it “What if Programming and Networking Had a Storage Baby” If you missed the live webcast, you can watch it on-demand. The discussion from our panel of experts generated a lot of good questions. As promised, here are answers to them all.  Q. With regard to persistent memory, how does one decide if it’s better to use load/store or access via I/O? A. Legacy applications will not change and hence will access the persistent memory the way they were written. If your legacy application needs a lot of memory and you want to use the new persistent memory as just a big and cheap (volatile) memory, then the access will be byte addressable (load/store). If your legacy application uses block storage then it will use the persistent memory using block addressing. New applications can take advantage of using byte addressing and persistency. They can keep all their data structures in memory, and these data structures will also be persistent! This saves applications the need to serialize before storing and to de-serialize when retrieving from storage and enables many other ways to optimize the software. Q. Can you go over again a bit more slowly how byte accessible and LBA change with persistent memory? A. Persistent memory can be accessed in three different ways.

1. Using byte addressing, in which case it behaves like a big (volatile) memory
2. Using logical block addressing, in which case it behaves like a block storage device
3. Using SNIA NVM Programming Model that enable byte addressing along with persistency. In this case byte being written into the device can be made persistent with special APIs

You can configure and decide what model is better use for your application. Q. Is that like flash? A. Persistent memory is a technology that is persistent like flash, but has byte addressing. It can be implemented using underlying flash, battery backed DRAM, Phase Change Memory and more. Q. You were going to parse out flash vs. NVMe, I think. Also, how will the elements discussed during the session impact these evolving technologies? A. Flash is a non-volatile memory technology that supports block addressing. PCM is another non-volatile technology which is newer that supports byte addressing (which implies that it can also do block addressing by emulation). NVMe describes an interface to access non-volatile memory technology, by placing the non-volatile memory over the PCI bus. Storage Class Memory is yet another interface to access non-volatile memory, by placing the non-volatile memory over the memory bus. With this in mind: 1) It is common to see NVMe devices with backing flash devices. They will support block addressable. They have the option to expose a small byte addressable memory buffer as well on the PCI (typically a DRAM), which may or may not be volatile. 2) It is common to see Storage Class Memory with backing PCM device, or with DRAM (that can backup itself to flash on power failure). They will support byte addressable. Q. Regarding SMB & CIFS protocols, is SMB or CIFS the deprecated one? A. The name CIFS hasn’t been used in a while; it’s now all SMB. SMB version1 is deprecated; see this Microsoft article. Don’t use CIFS! Q. Are there any rules of thumb in regards to the efficiency of block vs. file vs. object stores from the storage capacity overhead and network “busyness”? A. Effectively, as you get closer to the lower-level block storage devices, your storage networking architecture needs to become more deterministic. That is, you begin to start caring more about the number of hosts connecting to a particular storage target (fan-in ratio) and the ratio of bandwidth the target has compared to the bandwidth that the hosts connecting to it have (oversubscription). Highly-transactional block storage protocols, such as Fibre Channel, FCoE and lossless iSCSI, for example, will need to have very low oversubscription ratios (sometimes as low as 4:1, depending on the type of application/workload). Most are somewhat more forgiving, and 16:1 and 20:1 are not uncommon. When you move into file-based systems, that oversubscription can be a lot higher (there is no general rule of thumb here, but the oversubscription can be in the low hundreds:1). Object-based systems are so scaled and distributed, that there really are no oversubscription limits at all, because those systems are not highly transactional. Q. Does an object always have to be replaced in entirety? How do systems handle updates to large objects? A. The rule is that you shouldn’t take a lock on an object. Classically, the whole object should be replaced. Updating is not straightforward. Traditional “get/release” locking is too expensive in terms of latency over geographic distances, too hard to manage in a distributed environment, is hard to scale, needs recovery in the case of failure, and introduces state to what is basically storage built for stateless operations. Plus, the object may be sharded across multiple physical systems. Some object systems do allow what they call “pessimistic locking” (take a lock for a fixed period of time, say 10 seconds) but it’s not a true lock that you obtain then release. It’s more like a window of opportunity and is often called, and acts like, a lease. There are also other techniques, like “optimistic concurrency” (using a unique identifier, try and then check if your identifier was successful) and “last writer wins” (as it says, the last write is the one that the storage system remembers). Many systems do this by snapshotting the object, allowing updates on the copy, and then atomically swapping them. Object systems differ in what they permit. In general, applications need to be aware that they may, very occasionally, not be successful when modifying objects, and to have strategies to deal with it, like retrying or even simply giving up. Again, you can check out the recorded version of the webcast at your convenience and you can download the webcasts slides as well if you’d like to follow along. Remember, this webcast was part of series. I encourage you to register today for our next one, which will be on August 1^st at 10:00 am PT – Part Turquoise “Where Does My Data Go?” And please visit the SNIA ESF website for our full library of ESF webcasts.  

By now, we at the SNIA Storage Ethernet Storage Forum (ESF) hope you are familiar with (perhaps even a loyal fan of) the "Everything You Wanted To Know About Storage But Were Too Proud To Ask," popular webcast series. On August 1^st, the "Too Proud to Ask" train will make another stop. In this seventh session, "Everything You Wanted to Know About Storage But Were Too Proud To Ask: Turquoise - Where Does My Data Go?, we will take a look into the mysticism and magic of what happens when you send your data off into the wilderness. Once you click "save," for example, where does it actually go? When we start to dig deeper beyond the application layer, we often don't understand what happens behind the scenes. It's important to understand multiple aspects of the type of storage our data goes to along with their associated benefits and drawbacks as well as some of the protocols used to transport it. In this webcast we will explain:

• Volatile v Non-Volatile v Persistent Memory
• NVDIMM v RAM v DRAM v SLC v MLC v TLC v NAND v 3D NAND v Flash v SSDs v NVMe
• NVMe (the protocol)

Many people get nervous when they see that many acronyms, but all too often they come up in conversation, and you're expected to know all of them? Worse, you're expected to know the differences between them, and the consequences of using them? Even worse, you're expected to know what happens when you use the wrong one? We're here to help. It's an ambitious project, but these terms and concepts are at the heart of where compute, networking and storage intersect. Having a good grasp of these concepts ties in with which type of storage networking to use, and how data is actually stored behind the scenes. Register today to join us for this edition of the "Too Proud To Ask" series, as we work towards making you feel more comfortable in the strange, mystical world of storage. And don't let pride get in the way of asking any and all questions on this great topic. We will be there on August 1^st to answer them! Update: If you missed the live event, it's now available  on-demand. You can also  download the webcast slides.      

By now, we at the SNIA Storage Ethernet Storage Forum (ESF) hope you are familiar with (perhaps even a loyal fan of) the “Everything You Wanted To Know About Storage But Were Too Proud To Ask,” popular webcast series. On August 1^st, the “Too Proud to Ask” train will make another stop. In this seventh session, “Everything You Wanted to Know About Storage But Were Too Proud To Ask: Turquoise – Where Does My Data Go?, we will take a look into the mysticism and magic of what happens when you send your data off into the wilderness. Once you click “save,” for example, where does it actually go? When we start to dig deeper beyond the application layer, we often don’t understand what happens behind the scenes. It’s important to understand multiple aspects of the type of storage our data goes to along with their associated benefits and drawbacks as well as some of the protocols used to transport it. In this webcast we will explain:

• Volatile v Non-Volatile v Persistent Memory
• NVDIMM v RAM v DRAM v SLC v MLC v TLC v NAND v 3D NAND v Flash v SSDs v NVMe
• NVMe (the protocol)

Many people get nervous when they see that many acronyms, but all too often they come up in conversation, and you’re expected to know all of them? Worse, you’re expected to know the differences between them, and the consequences of using them? Even worse, you’re expected to know what happens when you use the wrong one? We’re here to help. It’s an ambitious project, but these terms and concepts are at the heart of where compute, networking and storage intersect. Having a good grasp of these concepts ties in with which type of storage networking to use, and how data is actually stored behind the scenes. Register today to join us for this edition of the “Too Proud To Ask” series, as we work towards making you feel more comfortable in the strange, mystical world of storage. And don’t let pride get in the way of asking any and all questions on this great topic. We will be there on August 1^st to answer them!