Welcome!

SDN Journal Authors: Michel Courtoy, Stefan Bernbo, Amitabh Sinha, Mike Wood, Liz McMillan

Blog Feed Post

VMware VVOL's and storage I/O fundamentals (Part I)

VMware VVOL's and storage I/O fundamentals (Part I)

By Greg Schulz

VMworld 2014

Note that this is a three part series with the first piece here (e.g. Are VMware VVOL's in your virtual server and storage I/O future?), the second piece here (e.g.VMware VVOL's and storage I/O fundamentals Part 1) and the third piece here (e.g. VMware VVOL's and storage I/O fundamentals Part 2).

VMware vSphere beta

Some of you may already be participating in the VMware beta of VVOL involving one of the initial storage vendors also in the beta program.

Here is the quick synopsis of VMware Virtual Volumes:

  • Higher level of abstraction of storage vs. traditional SCSI LUNs or NAS NFS mount points
  • Tighter level of integration and awareness between VMware hypervisors (guests and management) and storage systems
  • Simplified management for both storage and virtualization administrators removing complexity to support increased scaling
  • Enable automation and service managed aka software defined storage management across application and storage tiers

Ok, now let's go a bit deeper, however if you want some good music to listen to while reading this, check out @BruceRave GoDeepMusic.Net and shows here.

Taking a step back, digging deeper into Storage I/O and VVOL's fundamentals

Instead of a VM host accessing its virtual disk (aka VMDK) which is stored in a VMFS formatted data store (part of ESXi hypervisor) built on top of a SCSI LUN (e.g. SAS, SATA, iSCSI, Fibre Channel aka FC, FCoE aka FC over Ethernet, IBA/SRP, etc) or an NFS file system presented by a storage system (or appliance), VVOL's push more functionality and visibility down into the storage system. VVOL's shift more intelligence and work from the hypervisor down into the storage system. Instead of a storage system simply presenting a SCSI LUN or NFS mount point and having limited (coarse) to no visibility into how the underlying storage bits, bytes as well as blocks are being used, storage systems gain more awareness.

Keep in mind that even files and objects still get ultimately mapped to pages and blocks aka sectors even on nand flash-based SSD's. However also keep an eye on some new technology such as the Seagate Kinetic drive that instead of responding to SCSI block based commands, leverage object API's and associated software on servers. Read more about these emerging trends here and here at objectstoragecenter.com.

With a normal SCSI LUN the underlying storage system has no knowledge of how the upper level operating system, hypervisor, file system or application such as a database (doing raw IO) is allocating the pages or blocks of memory aka storage. It is up to the upper level storage and data management tools to map from objects and files to the corresponding extents, pages and logical block address (LBA) understood by the storage system. In the case of a NAS solution, there is a layer of abstractions placed over the underlying block storage handling file management and the associated file to LBA mapping activity.

Storage I/O basics
Storage I/O and IOP basics and addressing: LBA's and LBN's

Getting back to VVOL, instead of simply presenting a LUN which is essentially a linear range of LBA's (think of a big table or array) that the hypervisor then manages data placement and access, the storage system now gains insight into what LBA's correspond to various entities such as a VMDK or VMX, log, clone, swap or other VMware objects. With this more insight, storage systems can now do native and more granular functions such as clone, replication, snapshot among others as opposed to simply working on a coarse LUN basis. The similar concepts extend over to NAS NFS based access. Granted, there are more to VVOL's including ability to get the underlying storage system more closely integrated with the virtual machine, hypervisor and associated management including supported service manage and classes or categories of service across performance, availability, capacity, economics.

What about VVOL, VAAI and VASA?

VVOL's are building from earlier VMware initiatives including VAAI and VASA. With VAAI, VMware hypervisor's can off-load common functions to storage systems that support features such as copy, clone, zero copy among others like how a computer can off-load graphics processing to a graphics card if present.

VASA however provides a means for visibility, insight and awareness between the hypervisor and its associated management (e.g. vCenter etc) as well as the storage system. This includes storage systems being able to communicate and publish to VMware its capabilities for storage space capacity, availability, performance and configuration among other things.

With VVOL's VASA gets leveraged for unidirectional (e.g. two-way) communication where VMware hypervisor and management tools can tell the storage system of things, configuration, activities to do among others. Hence why VASA is important to have in your VMware CASA.

What's this object storage stuff?

VVOL's are a form of object storage access in that they differ from traditional block (LUN's) and files (NAS volumes/mount points). However, keep in mind that not all object storage are the same as there are object storage access and architectures.

object storage
Object Storage basics, generalities and block file relationships

Avoid making the mistake of when you hear object storage that means ANSI T10 (the folks that manage the SCSI command specifications) Object Storage Device (OSD) or something else. There are many different types of underlying object storage architectures some with block and file as well as object access front ends. Likewise there are many different types of object access that sit on top of object architectures as well as traditional storage system.

Object storage I/O
An example of how some object storage gets accessed (not VMware specific)

Also keep in mind that there are many different types of object access mechanism including HTTP Rest based, S3 (e.g. a common industry defacto standard based on Amazon Simple Storage Service), SNIA CDMI, SOAP, Torrent, XAM, JSON, XML, DICOM, IL7 just to name a few, not to mention various programmatic bindings or application specific implementations and API's. Read more about object storage architectures, access and related topics, themes and trends at www.objecstoragecenter.com

Lets take a break here and when you are ready, click here to read the third piece in this series VMware VVOL's and storage I/O fundamentals Part 2.

Ok, nuff said (for now)

Cheers gs

Greg Schulz - Author Cloud and Virtual Data Storage Networking (CRC Press), The Green and Virtual Data Center (CRC Press) and Resilient Storage Networks (Elsevier)
twitter @storageio

All Comments, (C) and (TM) belong to their owners/posters, Other content (C) Copyright 2006-2014 StorageIO All Rights Reserved

Read the original blog entry...

More Stories By Greg Schulz

Greg Schulz is founder of the Server and StorageIO (StorageIO) Group, an IT industry analyst and consultancy firm. Greg has worked with various server operating systems along with storage and networking software tools, hardware and services. Greg has worked as a programmer, systems administrator, disaster recovery consultant, and storage and capacity planner for various IT organizations. He has worked for various vendors before joining an industry analyst firm and later forming StorageIO.

In addition to his analyst and consulting research duties, Schulz has published over a thousand articles, tips, reports and white papers and is a sought after popular speaker at events around the world. Greg is also author of the books Resilient Storage Network (Elsevier) and The Green and Virtual Data Center (CRC). His blog is at www.storageioblog.com and he can also be found on twitter @storageio.

@CloudExpo Stories
A look across the tech landscape at the disruptive technologies that are increasing in prominence and speculate as to which will be most impactful for communications – namely, AI and Cloud Computing. In his session at 20th Cloud Expo, Curtis Peterson, VP of Operations at RingCentral, highlighted the current challenges of these transformative technologies and shared strategies for preparing your organization for these changes. This “view from the top” outlined the latest trends and developments i...
Cloud applications are seeing a deluge of requests to support the exploding advanced analytics market. “Open analytics” is the emerging strategy to deliver that data through an open data access layer, in the cloud, to be directly consumed by external analytics tools and popular programming languages. An increasing number of data engineers and data scientists use a variety of platforms and advanced analytics languages such as SAS, R, Python and Java, as well as frameworks such as Hadoop and Spark...
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend 21st Cloud Expo October 31 - November 2, 2017, at the Santa Clara Convention Center, CA, and June 12-14, 2018, at the Javits Center in New York City, NY, and learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
Automation is enabling enterprises to design, deploy, and manage more complex, hybrid cloud environments. Yet the people who manage these environments must be trained in and understanding these environments better than ever before. A new era of analytics and cognitive computing is adding intelligence, but also more complexity, to these cloud environments. How smart is your cloud? How smart should it be? In this power panel at 20th Cloud Expo, moderated by Conference Chair Roger Strukhoff, paneli...
@DevOpsSummit at Cloud Expo taking place Oct 31 - Nov 2, 2017, at the Santa Clara Convention Center, Santa Clara, CA, is co-located with the 21st International Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is ...
"We are a monitoring company. We work with Salesforce, BBC, and quite a few other big logos. We basically provide monitoring for them, structure for their cloud services and we fit into the DevOps world" explained David Gildeh, Co-founder and CEO of Outlyer, in this SYS-CON.tv interview at DevOps Summit at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
The current age of digital transformation means that IT organizations must adapt their toolset to cover all digital experiences, beyond just the end users’. Today’s businesses can no longer focus solely on the digital interactions they manage with employees or customers; they must now contend with non-traditional factors. Whether it's the power of brand to make or break a company, the need to monitor across all locations 24/7, or the ability to proactively resolve issues, companies must adapt to...
Cloud promises the agility required by today’s digital businesses. As organizations adopt cloud based infrastructures and services, their IT resources become increasingly dynamic and hybrid in nature. Managing these require modern IT operations and tools. In his session at 20th Cloud Expo, Raj Sundaram, Senior Principal Product Manager at CA Technologies, will discuss how to modernize your IT operations in order to proactively manage your hybrid cloud and IT environments. He will be sharing bes...
Join us at Cloud Expo June 6-8 to find out how to securely connect your cloud app to any cloud or on-premises data source – without complex firewall changes. More users are demanding access to on-premises data from their cloud applications. It’s no longer a “nice-to-have” but an important differentiator that drives competitive advantages. It’s the new “must have” in the hybrid era. Users want capabilities that give them a unified view of the data to get closer to customers and grow business. The...
Artificial intelligence, machine learning, neural networks. We’re in the midst of a wave of excitement around AI such as hasn’t been seen for a few decades. But those previous periods of inflated expectations led to troughs of disappointment. Will this time be different? Most likely. Applications of AI such as predictive analytics are already decreasing costs and improving reliability of industrial machinery. Furthermore, the funding and research going into AI now comes from a wide range of com...
For organizations that have amassed large sums of software complexity, taking a microservices approach is the first step toward DevOps and continuous improvement / development. Integrating system-level analysis with microservices makes it easier to change and add functionality to applications at any time without the increase of risk. Before you start big transformation projects or a cloud migration, make sure these changes won’t take down your entire organization.
"When we talk about cloud without compromise what we're talking about is that when people think about 'I need the flexibility of the cloud' - it's the ability to create applications and run them in a cloud environment that's far more flexible,” explained Matthew Finnie, CTO of Interoute, in this SYS-CON.tv interview at 20th Cloud Expo, held June 6-8, 2017, at the Javits Center in New York City, NY.
Internet of @ThingsExpo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The Internet of Things (IoT) is the most profound change in personal and enterprise IT since the creation of the Worldwide Web more than 20 years ago. All major researchers estimate there will be tens of billions devic...
SYS-CON Events announced today that MobiDev, a client-oriented software development company, will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. MobiDev is a software company that develops and delivers turn-key mobile apps, websites, web services, and complex software systems for startups and enterprises. Since 2009 it has grown from a small group of passionate engineers and business...
SYS-CON Events announced today that GrapeUp, the leading provider of rapid product development at the speed of business, will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place October 31-November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA. 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 acr...
SYS-CON Events announced today that Ayehu will exhibit at SYS-CON's 21st International Cloud Expo®, which will take place on October 31 - November 2, 2017 at the Santa Clara Convention Center in Santa Clara California. Ayehu provides IT Process Automation & Orchestration solutions for IT and Security professionals to identify and resolve critical incidents and enable rapid containment, eradication, and recovery from cyber security breaches. Ayehu provides customers greater control over IT infras...
What's the role of an IT self-service portal when you get to continuous delivery and Infrastructure as Code? This general session showed how to create the continuous delivery culture and eight accelerators for leading the change. Don Demcsak is a DevOps and Cloud Native Modernization Principal for Dell EMC based out of New Jersey. He is a former, long time, Microsoft Most Valuable Professional, specializing in building and architecting Application Delivery Pipelines for hybrid legacy, and cloud ...
With major technology companies and startups seriously embracing Cloud strategies, now is the perfect time to attend 21st Cloud Expo October 31 - November 2, 2017, at the Santa Clara Convention Center, CA, and June 12-14, 2018, at the Javits Center in New York City, NY, and learn what is going on, contribute to the discussions, and ensure that your enterprise is on the right path to Digital Transformation.
21st International Cloud Expo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, 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. Me...
DevOps at Cloud Expo, taking place October 31 - November 2, 2017, at the Santa Clara Convention Center in Santa Clara, CA, is co-located with 21st Cloud Expo and will feature technical sessions from a rock star conference faculty and the leading industry players in the world. The widespread success of cloud computing is driving the DevOps revolution in enterprise IT. Now as never before, development teams must communicate and collaborate in a dynamic, 24/7/365 environment. There is no time to w...