Nexsan Technologies — Green Storage

What is AutoMAID?  How is it different?  What’s in it for me?

Have you heard these questions?  Maybe you asked them yourself.  These are the most frequently asked questions we hear at Nexsan.  Maybe it’s because of rising energy prices or concerns about reducing costs. Whatever the cause, in recent months, we have seen a steady and growing interest around AutoMAID and in saving energy and cooling costs. 

The industry response to this excitement has been to create some confusion around this technology versus other approaches.

So, by popular demand, Nexsan has created three short audio podcasts addressing the three most frequently asked questions to help clarify AutoMAID and its benefits.  These podcasts are short, sweet and informative; you can download them to your MP3 player or computer for easy listening on the way to work or at your desk.

The link below will take you to these three new podcasts.

Listen to AutoMAID Podcasts

As you may have heard, we just announced our DATABeast storage solution, which incorporates the energy saving technologies for which we’ve become a little bit famous.  Today I’d like to offer some suggestions for optimizing AutoMAID in these and similar environments.

For those unfamiliar with AutoMAID, a brief tutorial:  imagine if you took a RAID shelf and added an optional mode which spins down arrays that are not being accessed, and that the spin down process is divided into three steps which save progressively more power.  You don’t access it for a couple of minutes and it goes into the first saving level which unloads the heads, saving power due to reduced aerodynamic resistance in the drives, then if it stays idle for a while longer, it slows to half the normal RPM, then finally if it’s idle for a long time it’s spun completely down and put into a low power sleep mode.

Many new storage offerings have the capability to virtualize huge amounts of storage and present it as a flat file system or a flat sea of blocks.  The DATABeast, for example, can build single physical LUNs as big as 64 terabytes, striping the data across many individual RAID sets in multiple disk shelves.  Very tempting to put all your storage in one huge volume, isn’t it?  But just because you can, doesn’t always mean you should.  Especially when trying to save power!

The problem is, that any type of striping arrangement means that just a small handful of host operations will very likely result in at least one operation to each RAID set, which means you are not saving much energy.  Many operations, such as read commands which don’t happen to hit our cache, will require us to spin up at least one drive of the RAID set and possibly all of them.  The same effect can happen when using LVM software on the host if you allow it to stripe data across all the RAIDs, or if you combine all the RAIDs into a ZFS pool.  This is fine if you have a deep archive application which is 100% idle for long periods of time, in which case the arrays will unload the heads, then go to half speed, and finally stop until you start hitting the storage again.

By arranging your data such that infrequently used data is pooled together, the pool may enjoy long periods of zero activity, in which case the AutoMAID savings are maximized.  Similarly, resist the temptation to store active data on arrays which are mostly there for future expansion – let them stay asleep until you need the TB.  DATABeast can let you add the arrays to an existing storage pool on the fly, whenever you need it, so there’s not much reason to add arrays until the space is required.   Our thin provisioning technology allows seamless expansion of existing volumes, with convenient operator alerts when approaching the watermark setpoints.

DATABeast also has tools which allow you to migrate your data from one storage pool to another, which will assist in maximizing your energy savings.  The reporting tool will provide information on utilization, which will help streamline your management decisions.  If you want to check your handiwork, each array gathers AutoMAID “efficiency” statistics, which will tell you how close you are to achieving maximum power savings.

In future blog posts we will dive a little deeper into power savings and offer additional ideas on how to streamline the process.  It’s easy being green!

Secrets want out.  The secret around idle disk drives is no different.  Joab Jackson at GCN (Government Computer News) reported that researchers from University of California and NetApp recently presented preliminary results of a study on data access patterns on NAS systems, “Most network data sits untouched”.  One key finding from this study is 90 percent of the files on servers are never accessed.

If 90 percent of the material on the servers was never accessed, why on earth is anyone paying to keep it running 24×7? What a no-brainer for AutoMAID (Nexsan’s proprietary energy-saving technology that reduces disk drive energy when disks are idle). 

From Mr. Jackson’s article . . .

“During the three-month period that the network was under scrutiny, more than 90 percent of the material on the servers was never accessed. The researchers captured packets encoded using the Common Internet File System protocol, which Microsoft Windows applications use to save data via a network. About 1.5T of data was transferred.

“Compared to the full amount of allocated storage on the file servers, this represents only 10 percent of data,” Leung said. “[This] means that 90 percent of the data is untouched during this three-month period.”

Moreover, among the files that were opened, 65 percent were only opened once. And most of the rest were opened five or fewer times, though about a dozen files were open 100,000 times or more.

“What this suggests, in general, is that files are infrequently re-accessed,” Leung said.”

Andrew Leung is a computer science researcher at the University of California and presented these findings at the USENIX conference in Boston.

Turning off the lights when they are not needed is one of the fastest, easiest and least expensive ways to save energy.  Why not do the same for your fixed content data and turn down energy use for your storage drives when they are idle? 

Better yet, why not treat the energy saving technology for disk drives like a dimmer switch.  You can dial down the energy use to match your application needs, but bring it back again right away. In a medical facility, a PACS image may sit idle for weeks and months, but when the doctor needs it in an emergency, the image needs to be instantly accessible.

Far too many administrators are wasting large amounts of energy (and, of course, money) because they think their storage systems need to run at full power 24×7.  Realizing the secret that storage is idle at times (especially on nights and weekends) is the first step towards significant savings.

The secret is getting out. 

There was a simple yet telling comment in the New York Times recently (‘The Rise of the Humble Engineer,’ June 17, 2008 ) from Chandrakant Patel, a mechanical engineer in HP Labs who oversees the company’s programs in energy-efficient data centers and technology.  He’s working on research focused on things like replacing cooper wiring in server computers with laser beams.  Very cool stuff.  But, he added ‘data centers can be made 30 percent to 50 percent more efficient by applying current technology.’

Bingo!  He hit it right on the head.  There is no doubt a great need for advanced new energy-efficient technologies exists, and we trust smart minds like Mr. Patel will unearth them.  But, there is also much that can be done right now, simply and cost effectively.  The technologies exist, and in many ways, they just need to be turned on.  

One simple and easy way to incorporate green storage technology is to purchase energy-saving storage that is designed into your normal, ongoing RAID storage purchases.  We feel strongly that energy efficiency should not be an afterthought or a separate consideration.  It should be designed in from the beginning, at no added cost and with no added technical decisions.  To this end, our AutoMAID technology comes as a standard feature on all Nexsan storage products at no extra charge.  Best of all, activating AutoMAID is as simple as changing a light bulb.

Everyday people are offered simple ways to save energy in their homes through the use of energy-efficient light bulbs.  AutoMAID offers a similarly user-friendly approach; it doesn’t require sophisticated or expensive software on the host computer or even a professional services engagement.  Data center administrators need only toggle a setting or two and they’re done—the system takes care of the rest.  It powers down according to user-defined settings, saving energy but not sacrificing performance because it returns to full activity nearly instantaneously.  Saving energy with AutoMAID is as simple as installing an energy-efficient light bulb and the effect can be more dramatic with power savings of 20-60 percent.

We’re cheering on Mr. Patel and the efforts of other brilliant engineers diligently working on new ways of tackling the energy challenges of data centers today and into the future.  And we also concur with this opinion that there is no reason to wait.  Significant energy savings, through the aggressive deployment of existing technologies, can and should be had today.