vPivot

Scott Drummonds on Virtualization

Server Flash + Array Flash

3 Comments »

With the recent general availability of VFCache, EMC has buzzed with ideas about what to do with server-based solid state storage.  Server-based solid state has been around for years.  I remember when Fusion-io visited us at VMware in 2009.  I spent a lot of time thinking about use cases, value, costs, and features. Now at EMC I am asking myself even bigger questions: how far can we go with this technology?  How much can we federate it, migrate data among nodes and within shared storage, protect it, and replicate it?  There are a lot of smart people in EMC that are way ahead of me on this.

But for the time being, the world is using server cache to speed up applications while living with mobility limitations.  Because of my performance background I am still a speed junky.  My long time in that field makes me a bit of a cynic, too.  When I saw a version of the following chart used in an internal EMC presentation I was skeptical.  Take at look at this and ask yourself if you believe it.

Read the rest of this entry »

The Flash Storage Revolution: Part III

11 Comments »

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.

Read the rest of this entry »

Justifying SSDs

10 Comments »

Ever since I saw the results of VMware’s first performance work on EMC’s Enterprise Flash Drives (EFDs) I knew the storage world was about to change.  Even though I love the idea of SSD, I still struggle with the justification of their purchase.  I have had trouble quantifying the value of an EFD and fearlessly committing customers’ money to their purchase.  In this article I want to offer a few thoughts on these devices as I formulate my own ideas as to when SSDs are needed and how we can all enjoy their benefits.

Read the rest of this entry »

Databases, Storage, and Solid State Disks

Comments Off on Databases, Storage, and Solid State Disks

A colleague of mine dropped by my desk on Friday to talk about storage best practices for virtualized databases (SQL Server in this case).  He observed a VMware deployment where the data and log files for a SQL Server virtual machine were consolidated on a single VMFS volume backed by a RAID 5 LUN.  “Is this a VMware best practice?” he asked.  “Should you not put the redo logs on a RAID 10 LUN?”  The answers are ‘no’ and ‘yes’, respectively.  And with the solid state disk (SSD) auto-tiering from EMC (FAST) the second answer is an emphatic “YES!”

Read the rest of this entry »