Primary Storage: The difference between flash Arrays and a bunch of SSD's

Posted by VIOLIN SYSTEMS on Feb 29, 2012 2:25:48 PM

Start From Flash

There is discussion in the industry as to the best method to deploy solid state storage, in other words whether it is better to build flash arrays from SSD's, PCIe Cards, or the flash chips themselves. The key to system design is selecting the right building blocks and integrating them in such a way that the overall system is optimized - while minimizing tradeoffs. Violin strongly believes that you need to start from the flash layer (chips), and build an array as a coherent, tightly integrated whole to extract the extraordinary value offered by these amazingly high performance flash die.

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Topics: commodity, Flash Array, solid state drive, PCIe, server, SSD

Part 4: SSD’s in Storage Arrays

Posted by VIOLIN SYSTEMS on Jan 10, 2012 2:41:35 PM

Why did we take disk drives out of servers?  Now we rely on traditional disk array storage and surround it with data center compute.  The industry doubles processing power every 12 to 18 months and Gigabit Ethernet and Infiniband now provide 10 – 40Gig bandwidth with very low latencies.  So we have lots of compute and we are swimming in bandwidth but the storage array hasn’t evolved at even 1/100 the pace?  The lack of IO is killing the applications.

Now in 2012 it seems clear that solid state storage will be the solution to balance the network-compute-storage triangle and provide the IO necessary to not only virtualize the easy applications but now tackle the hard (latency-sensitive) IO bound applications that have been fine tuned to run on dedicated servers.

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Topics: flash memory, flash storage, SSD, Storage Array

Sharing Solid State Storage

Posted by VIOLIN SYSTEMS on Dec 12, 2011 9:31:19 PM

George Crump of Storage Switzerland shot another chalk talk video, the subject of this one is sharing solid state storage. George added it to his article from a month ago where he shared his thoughts on Violin's certification with IBM SAN Volume Controller (SVC).

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Topics: memory arrays, SSD

Flash in the Data Center - Part 3 - What about PCIe Cards?

Posted by VIOLIN SYSTEMS on Sep 30, 2011 8:54:52 PM


Part 1 (Garbage Collection) and Part 2 (Commodity SSDs)

What about PCIe cards?

Another option is to pack as much flash as possible onto a PCIe card to sit in a high speed slot on a server.  Because of their much higher interface speeds, PCIe cards have much better performance than your typical commodity SSD, but face their own unique issues. To speak with the Operating System (OS)  PCIe cards require specialized software drivers.  With some cards these drivers are so heavy-weight that their vendors don't even call them drivers anymore but try to convince you they are a great value added software layer. That might be true except for the fact that those cards gain their performance by stealing CPU cycles from the core that’s hosting it, the same core running the business software your trying to accelerate. 

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Topics: IOPS, SSD

Flash in the Data Center? Part 2 - Why not off the shelf SSDs?

Posted by VIOLIN SYSTEMS on Sep 30, 2011 3:29:21 PM

In my last post I discussed a few of the technical aspects of flash that make it a unique storage media, particularly the complexity of garbage collection. Here we take a look at flash packaging and how that impacts architectural decisions. For this post I’ll focus on the question: “Should I use commodity SSDs?” and move on to PCIe cards and Enterprise Flash Drives in subsequent posts.

It’s easy to see why HDD form factor SSDs seem attractive: they have the same look and feel as a regular disk drive, they do usually weigh less, and they fit in the same HDD connectors you have in your existing server. That's all you need to see great flash speed, right? Sure they look good in the benchmarks, and while some benchmark sites have become a lot more sophisticated in measuring SSD performance, the SSDs have also become more sophisticated at Specsmanship.

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Flash in the Data Center? Part 1 – Roll your own and Garbage Collection

Posted by VIOLIN SYSTEMS on Sep 26, 2011 8:08:04 PM

Flash is coming to the data center. Contrary to perception 18 months ago, now this seems to be accepted as ‘common knowledge.’ There is still much discussion around what that flash will look like and in what form it will be consumed. I plan to write a series of blogs describing the unique challenges involved in building large flash Memory Arrays and some of the decisions made along the road. A good place to start with is the “let’s build it myself” group of folks and the challenges they will encounter.
The very adventuresome amongst you might start with, "I'll just make my own".

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Topics: groomer, MLC, garbage collection, grooming, IOPS, SLC, SSD