How’s Your Flash Doing?

By Joe Hyde

Assessing Flash Effectiveness

How’s your Flash doing? Admittedly, this is a bit of a loaded question. It could come from your boss, a colleague or someone trying to sell you the next storage widget. Since most customers are letting the vendors’ proprietary storage management algorithms optimize their enterprise storage automatically you may not have had the time or tools to quantify how your Flash is performing.

The Back-end Activity

First, let’s use the percentage of back-end activity to Flash as the metric to answer this question. Digging a little deeper we can look at back-end response times for Flash and spinning disks (let’s call these HDD for Hard Disk Drives). I’ll also look at the amount of sequential activity over the day to help explain the back-end behavior.

Below is 5 weekdays worth of data from an IBM DS8870 installed at a Fortune 500 company. Although it’s possible to place data statically on Flash storage in the IBM DS8870, in this case, IBM’s Easy Tier is used for the automatic placement of data across Flash and HDD storage tiers. Let’s refer to this scheme generically as auto-tiering. For this IBM DS8870, Flash capacity was roughly 10% of the total storage capacity. Continue reading

Do SSDs Make Storage Performance a Lost Art?

Lee

By Lee LaFrese

Storage Performance Analysts never get a break.  They only seem to get credit when there is some sort of crisis and their reward is often 12-hour work days and exposure to intense management scrutiny.  When things are running smoothly they tend to be ignored or redeployed to other projects.  With the advent of SSDs that are becoming ever more pervasive and affordable for Enterprise class applications, storage vendors are suggesting that storage performance issues are a thing of the past.  But let’s take a closer look at how SSDs are used in today’s Enterprise Storage before we decide if this is really true.

Today, there is a whole spectrum of SSD use cases in the Enterprise.  Generally, SSDs have been deployed in the same storage systems that support HDDs although lately there have been a number of All Flash Arrays (AFAs) that have come to market.  AFAs are for the most part simply a collection of flash memory using hardware that is more tuned to the storage capabilities.  An SSD is just a collection of flash memory and a controller so at a very basic level you can think of an AFA as a super-sized SSD!

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What Enterprise Storage system vendors won’t tell you about SSDs

Lee

By Lee LaFrese

For some time, Enterprise Storage vendors have touted Solid State Devices (SSDs) as a true game changer. They talk about nearly infinite performance and little energy usage compared to spinning disk drives.  They promote dynamic tiering software as the best way to assure that the workloads are optimized for SSDs. But will slapping a few SSDs into a storage frame really turn a Mack truck into a Ferrari?  And are SSDs truly the land of milk and honey they are portrayed to be? While there is a lot of truth to the claims, there are many things you are not hearing about SSDs. Here are some points that storage vendors should be telling you but are not talking about very much.

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