Welcome!

Industrial IoT Authors: Elizabeth White, Stackify Blog, Yeshim Deniz, SmartBear Blog, Liz McMillan

Related Topics: Containers Expo Blog, Industrial IoT, Microservices Expo, Machine Learning

Containers Expo Blog: Blog Feed Post

The Many Places You Can Go with SSD Caching Software

SSDs are a disruptive technology in that they are clearly changing the enterprise storage market

Disruptive technology is a term used to describe an idea or invention that typically disrupts an existing market, often completely displacing an earlier technology.  Sometimes disruptive is great (e.g. digital cameras and cell phones), and sometimes disruptive is not so great (e.g. laser video disks).  SSDs are a disruptive technology in that they are clearly changing the enterprise storage market.  The verdict is still out on just how disruptive SSDs will be; as is the case with many disruptive technologies, it is going to take some time to figure out exactly what to do with SSDs.  But a clear leader in the employment of SSDs is to use them as cache, which takes advantage of their incredibly high speeds, while minimizing the cost and hassle of implementation.

One of the key design decisions during the early development of VeloBit HyperCache was figuring out the optimal location of an SSD-based cache.  By “location,” I am referring to the placement of SSD within a computer’s storage architecture.  In order to understand VeloBit’s place in the storage stack, it is first necessary to understand the basic layout of a typical computer storage system.

Figure 1 shows a simplified IT system architecture model where the application software sits atop the operating system (OS) and corresponding file system.  The file system interfaces to HDDs and SSD using a block device driver.  The block device driver performs the actual IO with the HDDs and SSDs.  Hard disks in enterprise environments typically sit behind storage controllers, which contain their own (typically volatile) cache, along with a array of disks.  SSDs can also sit behind these storage controllers, although the VeloBit model allows you to directly attach an SSD to your server, without the need to purchase expensive specialty SSD arrays.

Additionally, in typical deployments, file systems sit atop a volume virtualization layer. In Linux, this is typically the LVM, or Linux Volume Manager.  Using this technology allows system administrators the flexibility of storage virtualization (such as RAID, snapshots, thin provisioning, and disk expansion) without incurring the added cost of SAN-side virtualization platforms.  Finally, it’s possible to deploy SSD caching as a part of this virtualization layer, as will be discussed later in this article.

SSD Caching SW locations resized 600

Figure 1: Simplified IT System Architecture

Back to deploying SSD as cache - there are two components to any SSD caching system: (1) the SSD itself, and (2) SSD caching software.  The SSD can either be installed in the server directly, or inside the storage array.  SSD caching software is more flexible, and be installed in several different locations:

  1. In the storage controller
  2. Between the volume virtualization layer and the block device layer
  3. As a part of the volume virtualization layer itself
  4. On top of the file system

These locations are marked on the diagram in Figure 1 with the corresponding circled numbers.

Let’s talk about the pros and cons of each location.

SSD Caching Software In The Storage Controller
Location 1 in Figure 1 shows the SSD caching software residing in the storage controller.  These controllers contain dedicated processors to manage all IO operations to the storage array, and algorithms can be implemented to determine what data should reside on the slower, higher-capacity disks, and what data should be sent to SSD for high-speed access. This solution:
•    Is easy to install, assuming you’re already purchasing a storage array
•    Provides very high performance
•    Can be incredibly expensive, since it comes along with an enterprise storage system
•    Is usually hardware dependent and typically vendor specific (results in vendor lock-in)


Examples of this solution would be SSD cards from High Point and LSI.

SSD Caching Software Above the Block Layer
A device driver is typically software developed to control specific hardware at a very low level.  In this case, I am grouping the SSD in with SSD caching software and calling the whole thing a device driver because the combination of the SSD and SSD caching software acts as a transparent device driver for an application accessing primary storage.  This is shown as the dashed line in location 2 in Figure 1. The SSD/Caching software combination is:
•    Easy to install – this implementation is completely transparent to both the lower-level storage, as well as all file systems and applications.
•    High performance
•    Very hard to develop – being such a low-level driver requires intimate knowledge of the operating system and block device drivers.
•    Hardware independent – since there’s no direct interaction with storage (storage access is abstracted by the block device driver), this solution works with any primary storage and SSD.
•    Applications independent – by inserting itself just above the block device driver, this type of SSD cache requires no file system or application changes.


Velobit HyperCache SSD caching software is an example of this solution.

SSD Cache In the Volume Virtualization Layer
The use of SSD caching software at location 3 in Figure 1 means the SSD caching software works inside the volume virtualization layer. This requires changes in the existing hard drive and SSD map configuration.  Using SSD caching software at this location is:
•    Moderate performance – performance can be limited by the virtualization layer itself.
•    Easy to develop – this caching method uses already-existing tools, inside the virtualization layer.
•    Very difficult to install – since the cache is built as a new virtual volume, your entire volume management needs to change to use the cache.
•    Hardware independent

FlashCache from Facebook is an example of this solution.


SSD Caching Software On Top Of The File System
The use of SSD caching software at location 4 in Figure 1 means the SSD caching software works at a higher level – the file system level. By sitting above, or inside, the file system, a user can specify precisely which files (and by association, applications) to cache.  Using SSD caching software at this location is:
•    Low performance
•    Very easy to develop
•    Very easy to install
•    Hardware independent
•    Environment specific – many databases don’t use a file system, to achieve maximum possible performance; therefore, file system-based caching won’t work in these environments.  Additionally, while most Windows installations use NTFS, many file systems exist for Linux, and it isn’t practical to support all available platforms.

CacheWorks from Nevex is an example of this solution.

Conclusion
The table below summarizes the various installations of SSD caching software discussed above.  If vendor lock-in is not a concern, running SSD caching software in the SSD controller offers the best combination of features and performance.  However, vendor lock-in is expensive and limits the options for product choices.  Using SSD caching software in conjunction with the SSD as a device driver for the HDD offers all the benefits of installing in the SSD controller without the problem of vendor lock-in.

Table SSD Caching SW locations

Read the original blog entry...

More Stories By Peter Velikin

Peter Velikin has 12 years of experience creating new markets and commercializing products in multiple high tech industries. Prior to VeloBit, he was VP Marketing at Zmags, a SaaS-based digital content platform for e-commerce and mobile devices, where he managed all aspects of marketing, product management, and business development. Prior to that, Peter was Director of Product and Market Strategy at PTC, responsible for PTC’s publishing, content management, and services solutions. Prior to PTC, Peter was at EMC Corporation, where he held roles in product management, business development, and engineering program management.

Peter has an MS in Electrical Engineering from Boston University and an MBA from Harvard Business School.

@ThingsExpo Stories
DX World EXPO, LLC, a Lighthouse Point, Florida-based startup trade show producer and the creator of "DXWorldEXPO® - Digital Transformation Conference & Expo" has announced its executive management team. The team is headed by Levent Selamoglu, who has been named CEO. "Now is the time for a truly global DX event, to bring together the leading minds from the technology world in a conversation about Digital Transformation," he said in making the announcement.
"Space Monkey by Vivent Smart Home is a product that is a distributed cloud-based edge storage network. Vivent Smart Home, our parent company, is a smart home provider that places a lot of hard drives across homes in North America," explained JT Olds, Director of Engineering, and Brandon Crowfeather, Product Manager, at Vivint Smart Home, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that Conference Guru has been named “Media Sponsor” of the 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. A valuable conference experience generates new contacts, sales leads, potential strategic partners and potential investors; helps gather competitive intelligence and even provides inspiration for new products and services. Conference Guru works with conference organizers to pass great deals to gre...
The Internet of Things will challenge the status quo of how IT and development organizations operate. Or will it? Certainly the fog layer of IoT requires special insights about data ontology, security and transactional integrity. But the developmental challenges are the same: People, Process and Platform. In his session at @ThingsExpo, Craig Sproule, CEO of Metavine, demonstrated how to move beyond today's coding paradigm and shared the must-have mindsets for removing complexity from the develop...
In his Opening Keynote at 21st Cloud Expo, John Considine, General Manager of IBM Cloud Infrastructure, led attendees through the exciting evolution of the cloud. He looked at this major disruption from the perspective of technology, business models, and what this means for enterprises of all sizes. John Considine is General Manager of Cloud Infrastructure Services at IBM. In that role he is responsible for leading IBM’s public cloud infrastructure including strategy, development, and offering m...
"Evatronix provides design services to companies that need to integrate the IoT technology in their products but they don't necessarily have the expertise, knowledge and design team to do so," explained Adam Morawiec, VP of Business Development at Evatronix, in this SYS-CON.tv interview at @ThingsExpo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
To get the most out of their data, successful companies are not focusing on queries and data lakes, they are actively integrating analytics into their operations with a data-first application development approach. Real-time adjustments to improve revenues, reduce costs, or mitigate risk rely on applications that minimize latency on a variety of data sources. In his session at @BigDataExpo, Jack Norris, Senior Vice President, Data and Applications at MapR Technologies, reviewed best practices to ...
Widespread fragmentation is stalling the growth of the IIoT and making it difficult for partners to work together. The number of software platforms, apps, hardware and connectivity standards is creating paralysis among businesses that are afraid of being locked into a solution. EdgeX Foundry is unifying the community around a common IoT edge framework and an ecosystem of interoperable components.
Large industrial manufacturing organizations are adopting the agile principles of cloud software companies. The industrial manufacturing development process has not scaled over time. Now that design CAD teams are geographically distributed, centralizing their work is key. With large multi-gigabyte projects, outdated tools have stifled industrial team agility, time-to-market milestones, and impacted P&L stakeholders.
"Akvelon is a software development company and we also provide consultancy services to folks who are looking to scale or accelerate their engineering roadmaps," explained Jeremiah Mothersell, Marketing Manager at Akvelon, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
"IBM is really all in on blockchain. We take a look at sort of the history of blockchain ledger technologies. It started out with bitcoin, Ethereum, and IBM evaluated these particular blockchain technologies and found they were anonymous and permissionless and that many companies were looking for permissioned blockchain," stated René Bostic, Technical VP of the IBM Cloud Unit in North America, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Conventi...
In his session at 21st Cloud Expo, Carl J. Levine, Senior Technical Evangelist for NS1, will objectively discuss how DNS is used to solve Digital Transformation challenges in large SaaS applications, CDNs, AdTech platforms, and other demanding use cases. Carl J. Levine is the Senior Technical Evangelist for NS1. A veteran of the Internet Infrastructure space, he has over a decade of experience with startups, networking protocols and Internet infrastructure, combined with the unique ability to it...
22nd International Cloud Expo, taking place June 5-7, 2018, at the Javits Center in New York City, NY, and co-located with the 1st DXWorld Expo will feature technical sessions from a rock star conference faculty and the leading industry players in the world. Cloud computing is now being embraced by a majority of enterprises of all sizes. Yesterday's debate about public vs. private has transformed into the reality of hybrid cloud: a recent survey shows that 74% of enterprises have a hybrid cloud ...
"Cloud Academy is an enterprise training platform for the cloud, specifically public clouds. We offer guided learning experiences on AWS, Azure, Google Cloud and all the surrounding methodologies and technologies that you need to know and your teams need to know in order to leverage the full benefits of the cloud," explained Alex Brower, VP of Marketing at Cloud Academy, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clar...
Gemini is Yahoo’s native and search advertising platform. To ensure the quality of a complex distributed system that spans multiple products and components and across various desktop websites and mobile app and web experiences – both Yahoo owned and operated and third-party syndication (supply), with complex interaction with more than a billion users and numerous advertisers globally (demand) – it becomes imperative to automate a set of end-to-end tests 24x7 to detect bugs and regression. In th...
"MobiDev is a software development company and we do complex, custom software development for everybody from entrepreneurs to large enterprises," explained Alan Winters, U.S. Head of Business Development at MobiDev, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
Coca-Cola’s Google powered digital signage system lays the groundwork for a more valuable connection between Coke and its customers. Digital signs pair software with high-resolution displays so that a message can be changed instantly based on what the operator wants to communicate or sell. In their Day 3 Keynote at 21st Cloud Expo, Greg Chambers, Global Group Director, Digital Innovation, Coca-Cola, and Vidya Nagarajan, a Senior Product Manager at Google, discussed how from store operations and ...
"There's plenty of bandwidth out there but it's never in the right place. So what Cedexis does is uses data to work out the best pathways to get data from the origin to the person who wants to get it," explained Simon Jones, Evangelist and Head of Marketing at Cedexis, in this SYS-CON.tv interview at 21st Cloud Expo, held Oct 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA.
SYS-CON Events announced today that CrowdReviews.com has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5–7, 2018, at the Javits Center in New York City, NY. CrowdReviews.com is a transparent online platform for determining which products and services are the best based on the opinion of the crowd. The crowd consists of Internet users that have experienced products and services first-hand and have an interest in letting other potential buye...
SYS-CON Events announced today that Telecom Reseller has been named “Media Sponsor” of SYS-CON's 22nd International Cloud Expo, which will take place on June 5-7, 2018, at the Javits Center in New York, NY. Telecom Reseller reports on Unified Communications, UCaaS, BPaaS for enterprise and SMBs. They report extensively on both customer premises based solutions such as IP-PBX as well as cloud based and hosted platforms.