|By Peter Velikin||
|April 5, 2012 08:30 AM EDT||
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.
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:
- In the storage controller
- Between the volume virtualization layer and the block device layer
- As a part of the volume virtualization layer itself
- 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.
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.
NHK, Japan Broadcasting, will feature the upcoming @ThingsExpo Silicon Valley in a special 'Internet of Things' and smart technology documentary that will be filmed on the expo floor between November 3 to 5, 2015, in Santa Clara. NHK is the sole public TV network in Japan equivalent to the BBC in the UK and the largest in Asia with many award-winning science and technology programs. Japanese TV is producing a documentary about IoT and Smart technology and will be covering @ThingsExpo Silicon Val...
Apr. 29, 2017 02:30 AM EDT Reads: 9,336
The 20th International Cloud Expo has announced that its Call for Papers is open. Cloud Expo, to be held June 6-8, 2017, at the Javits Center in New York City, brings together Cloud Computing, Big Data, Internet of Things, DevOps, Containers, Microservices and WebRTC to one location. With cloud computing driving a higher percentage of enterprise IT budgets every year, it becomes increasingly important to plant your flag in this fast-expanding business opportunity. Submit your speaking proposal ...
Apr. 29, 2017 01:45 AM EDT Reads: 1,547
SYS-CON Events announced today that CollabNet, a global leader in enterprise software development, release automation and DevOps solutions, will be a Bronze Sponsor of SYS-CON's 20th International Cloud Expo®, taking place from June 6-8, 2017, at the Javits Center in New York City, NY. CollabNet offers a broad range of solutions with the mission of helping modern organizations deliver quality software at speed. The company’s latest innovation, the DevOps Lifecycle Manager (DLM), supports Value S...
Apr. 29, 2017 01:45 AM EDT Reads: 1,271
The age of Digital Disruption is evolving into the next era – Digital Cohesion, an age in which applications securely self-assemble and deliver predictive services that continuously adapt to user behavior. Information from devices, sensors and applications around us will drive services seamlessly across mobile and fixed devices/infrastructure. This evolution is happening now in software defined services and secure networking. Four key drivers – Performance, Economics, Interoperability and Trust ...
Apr. 29, 2017 12:30 AM EDT Reads: 931
With billions of sensors deployed worldwide, the amount of machine-generated data will soon exceed what our networks can handle. But consumers and businesses will expect seamless experiences and real-time responsiveness. What does this mean for IoT devices and the infrastructure that supports them? More of the data will need to be handled at - or closer to - the devices themselves.
Apr. 29, 2017 12:00 AM EDT Reads: 1,042
With major technology companies and startups seriously embracing IoT strategies, now is the perfect time to attend @ThingsExpo 2016 in New York. Learn what is going on, contribute to the discussions, and ensure that your enterprise is as "IoT-Ready" as it can be! Internet of @ThingsExpo, taking place June 6-8, 2017, at the Javits Center in New York City, New York, is co-located with 20th Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry p...
Apr. 28, 2017 10:45 PM EDT Reads: 1,448
In his keynote at @ThingsExpo, Chris Matthieu, Director of IoT Engineering at Citrix and co-founder and CTO of Octoblu, focused on building an IoT platform and company. He provided a behind-the-scenes look at Octoblu’s platform, business, and pivots along the way (including the Citrix acquisition of Octoblu).
Apr. 28, 2017 10:30 PM EDT Reads: 1,618
Grape Up is a software company, specialized in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market across the USA and Europe, we work with a variety of customers from emerging startups to Fortune 1000 companies.
Apr. 28, 2017 10:30 PM EDT Reads: 2,497
Financial Technology has become a topic of intense interest throughout the cloud developer and enterprise IT communities. Accordingly, attendees at the upcoming 20th Cloud Expo at the Javits Center in New York, June 6-8, 2017, will find fresh new content in a new track called FinTech.
Apr. 28, 2017 10:15 PM EDT Reads: 2,524
SYS-CON Events announced today that Interoute, owner-operator of one of Europe's largest networks and a global cloud services platform, has been named “Bronze Sponsor” of SYS-CON's 20th Cloud Expo, which will take place on June 6-8, 2017 at the Javits Center in New York, New York. Interoute is the owner-operator of one of Europe's largest networks and a global cloud services platform which encompasses 12 data centers, 14 virtual data centers and 31 colocation centers, with connections to 195 add...
Apr. 28, 2017 09:45 PM EDT Reads: 2,180
Multiple data types are pouring into IoT deployments. Data is coming in small packages as well as enormous files and data streams of many sizes. Widespread use of mobile devices adds to the total. In this power panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists will look at the tools and environments that are being put to use in IoT deployments, as well as the team skills a modern enterprise IT shop needs to keep things running, get a handle on all this data, and deli...
Apr. 28, 2017 09:15 PM EDT Reads: 2,636
The Internet of Things is clearly many things: data collection and analytics, wearables, Smart Grids and Smart Cities, the Industrial Internet, and more. Cool platforms like Arduino, Raspberry Pi, Intel's Galileo and Edison, and a diverse world of sensors are making the IoT a great toy box for developers in all these areas. In this Power Panel at @ThingsExpo, moderated by Conference Chair Roger Strukhoff, panelists discussed what things are the most important, which will have the most profound e...
Apr. 28, 2017 08:15 PM EDT Reads: 2,407
@ThingsExpo has been named the Most Influential ‘Smart Cities - IIoT' Account and @BigDataExpo has been named fourteenth by Right Relevance (RR), which provides curated information and intelligence on approximately 50,000 topics. In addition, Right Relevance provides an Insights offering that combines the above Topics and Influencers information with real time conversations to provide actionable intelligence with visualizations to enable decision making. The Insights service is applicable to eve...
Apr. 28, 2017 07:45 PM EDT Reads: 2,950
SYS-CON Events announced today that Grape Up will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on Oct. 31 – Nov 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. Grape Up is a software company specializing in cloud native application development and professional services related to Cloud Foundry PaaS. With five expert teams that operate in various sectors of the market across the U.S. and Europe, Grape Up works with a variety of customers from emergi...
Apr. 28, 2017 07:15 PM EDT Reads: 2,331
DevOps is often described as a combination of technology and culture. Without both, DevOps isn't complete. However, applying the culture to outdated technology is a recipe for disaster; as response times grow and connections between teams are delayed by technology, the culture will die. A Nutanix Enterprise Cloud has many benefits that provide the needed base for a true DevOps paradigm.
Apr. 28, 2017 07:00 PM EDT Reads: 1,181
SYS-CON Events announced today that T-Mobile will exhibit at SYS-CON's 20th International Cloud Expo®, which will take place on June 6-8, 2017, at the Javits Center in New York City, NY. As America's Un-carrier, T-Mobile US, Inc., is redefining the way consumers and businesses buy wireless services through leading product and service innovation. The Company's advanced nationwide 4G LTE network delivers outstanding wireless experiences to 67.4 million customers who are unwilling to compromise on ...
Apr. 28, 2017 04:15 PM EDT Reads: 1,419
@GonzalezCarmen has been ranked the Number One Influencer and @ThingsExpo has been named the Number One Brand in the “M2M 2016: Top 100 Influencers and Brands” by Analytic. Onalytica analyzed tweets over the last 6 months mentioning the keywords M2M OR “Machine to Machine.” They then identified the top 100 most influential brands and individuals leading the discussion on Twitter.
Apr. 28, 2017 04:00 PM EDT Reads: 1,425
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend @CloudExpo | @ThingsExpo, June 6-8, 2017, at the Javits Center in New York City, NY and October 31 - November 2, 2017, Santa Clara Convention Center, CA. Learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
Apr. 28, 2017 03:30 PM EDT Reads: 1,516
20th Cloud Expo, taking place June 6-8, 2017, at the Javits Center in New York City, NY, 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 strategy.
Apr. 28, 2017 02:30 PM EDT Reads: 3,276
Five years ago development was seen as a dead-end career, now it’s anything but – with an explosion in mobile and IoT initiatives increasing the demand for skilled engineers. But apart from having a ready supply of great coders, what constitutes true ‘DevOps Royalty’? It’ll be the ability to craft resilient architectures, supportability, security everywhere across the software lifecycle. In his keynote at @DevOpsSummit at 20th Cloud Expo, Jeffrey Scheaffer, GM and SVP, Continuous Delivery Busine...
Apr. 28, 2017 02:15 PM EDT Reads: 1,196