vPivot

Scott Drummonds on Virtualization

VMware Thin Disks on EMC Virtual Provisioning

February 1st, 2012
Feb, 01 2012
2 Comments »

Even before I left VMware for EMC I was being asked to comment on “thin on thin”: the use of VMware thin VMDKs on virtually/thin provisioned storage.  As a VMware employee I recommended VMware’s thin provisioning but referred to storage vendors for their own best practices.

Now, as a member of the storage vendor community, I will answer for EMC. I will do so with detailed text from an outstanding TechBook I recently discovered on EMC’s Powerlink. This paper, Using Symmetrix Storage in VMware vSphere Environments (Version 7), provides incredible detail on the relationship between VMware thin disks and Symmetrix virtual provisioning. Its guidance is clear and simple.

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SIOC Alarm FAQ

January 10th, 2012
Jan, 10 2012
3 Comments »

In today’s post I want to update and amplify thoughts from an old post on Storage IO Control (SIOC).  VMware customers that are using SIOC may sometimes see the following vCenter alarm:

Non-VI workload detected on the datastore

Or you may see the following warning in the vSphere client:

An external I/O activity is detected on datastore …

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Flash Or SSD? (or: Why Interfaces Matter)

November 22nd, 2011
Nov, 22 2011
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In my three part series on flash I interchangeably used the terms “flash” and “SSD”.  In a recent article on this subject, Steven Foskett on IBM’s Storage Community successfully convinced me that I should stop using these terms interchangeably.  He then suggested that flash would persevere while SSD would not.  I disagree.

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The Flash Storage Revolution: Part III

November 17th, 2011
Nov, 17 2011
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In this final installment of the series, I will provide some detail behind flash storage sizing.  My previous entry contained an analytical and theoretical approach to sizing flash in today’s storage.  When I first studied the ideas I introduced in that post, I thought the flash sizing exercise was hopeless.  After all, how are customers to measure data cooling?  How could a storage admin quantify skew?

As it turns out, familiarity with these abstract concepts is not needed to size flash in your environment.  The same principles that Intel and AMD apply in sizing microprocessor cache can be applied to storage.  There are generalizations that will suit the majority of deployments.

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The Flash Storage Revolution: Part II

October 13th, 2011
Oct, 13 2011
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In the previous entry on this ongoing series covering the flash storage revolution, I concluded that flash is now an essential part of enterprise storage. But its value proposition is hinged on high utilization. High utilization cannot be sustained without efficient auto-tiering or accurate cache sizing for flash-based cache.

This article will describe the theory behind optimal cache sizing.  Practical guidance will follow in part three, the last entry in this series. I will again lean heavily on Denis Vilfort’s presentation that I offer for download on my blog.

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The Flash Storage Revolution: Part I

October 4th, 2011
Oct, 04 2011
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Six weeks ago I finally upgraded my MacBook to solid state storage.  The change in performance is so dramatic, to say the least.  I have been selling flash storage to EMC’s customers for over a year now and they have been loving it.  But I did not really get how valuable flash is until I saw it on my own laptop.

After this revolution of my own mind, I want to dedicate a few blog entries to the issue of solid state storage in the enterprise.  First I want to frame the problem that flash both solves and causes.  In the second entry I will introduce some of the theory behind flash sizing.  My last article will give you some very simple practical advice on how to use flash in your enterprise.

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vStorage APIs for Storage Awareness (VASA)

July 26th, 2011
Jul, 26 2011
5 Comments »

I am currently in Beijing halfway through a five city roadshow to present and listen to EMC’s technical pre-sales team. One of my roles in this traveling show is to talk about vSphere 5, and all of the great things EMC is doing to make it even better for customers. A big part of my talk is centered around the new vStorage API for Storage Awareness, or VASA. I think this new API is going to provide value far beyond what most people realize.

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VMware Linked Clone IO Implications

May 16th, 2011
May, 16 2011
2 Comments »

A month ago I was in Palo Alto seeing old friends and talking VMware. I spent some time with an old friend in performance engineering talking about vSphere’s implementation of linked clones. Conceptually I know linked clones require an additional map to translate the guest’s view of a contiguous file system into a reordered collection of blocks in multiple VMDK files. But I was not sure exactly how this technology worked and love hearing details. I want to share a few comments about this discussion.

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MLC Flash Versus SLC Flash

May 10th, 2011
May, 10 2011
1 Comment »

EMC’s recent announcement at EMC World of Project Lightning documents a program to increase the use of flash devices in enterprise storage. The project includes increased use of flash storage in EMC arrays, all-flash storage configurations, and support for Multi-layer Cell (MLC) flash. This last subject–MLC flash and its difference from SLC flash–piqued my curiosity.

Many years ago I studied electrical engineering. I was an awful at it. Analog was never my thing. I much prefer ones and zeroes. But I challenge myself to think about electronics once every blue moon. So I decided to delve into SLC and MLC flash technologies to understand how they differ and why we should care.  The content below summarizes my online research and the little bit I remember from school. If you can add, correct, or update this article I would be happy to have your comments.

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Bring Storage and VI Admins Together

February 13th, 2011
Feb, 13 2011
4 Comments »

Three years ago I was not a very big fan of EMC.  We at VMware worked very hard to show the world that we were not under EMC’s thumb.  In many respects, this meant pursuing projects with EMC’s competitors before engaging EMC.  EMC was partly to blame for this. EMC’s best argument to win the VMware footprint was based on a claim of majority ownership.  That pointless claim offends VMware employees and does not translate into value in VMware environments.

But things started changing a couple years ago.  Through the heroic efforts of Chad Sakac, EMC stopped acting like it deserved the business of VMware’s customers and more like it had to earn that business.  I noticed this in the way we partnered at multiple EMC Worlds and VMworlds.  I started to hear EMC’s name mentioned when we were prototyping features and products like VAAI, SRM, and SIOC.  EMC employees started treating us more like partners than indentured servants.  And then EMC started releasing products that were making the lives of VMware’s customers easier.

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