How Green is your SAN?

Being green is all the buzz these days. You have HDS growing foliage out of their storage systems on their home page, SNIA stirring up Green Standards, and every other vendor out there clamoring about how green they are, even if they’re not. Howard Goldstein has a great spin on all the hype in his green storage networking video clip.

Green storage can mean many different things and be spun just about every way you can imagine, so here is my spin, which I like to think is a little more factual. I see the most important factor being storage utilization efficiency. Software features like thin provisioning greatly improve storage utilization and minimize unused spinning disks. LeftHand’s Thin Provisioning software uses allocate-on-write technology, which means “reservationless storage” – no need to provision a bunch of storage to a volume that may take years to fill up.

Another obvious focus area is power consumption, or how power hungry your storage processors and disk shelves are. Thin Provisioning saves power by eliminating the allocated-but-unused spinning disks. Need proof of its value? Look at our competitors. Thin Provisioning is included in our base software offering and we don’t charge extra for it. Now that other vendors have finally caught up (HDS for example), they are making a huge deal out of it, and charging a considerable sum for it.

Another example of power saving technology is LeftHand’s Virtual SAN Appliance (VSA). This software can take stranded storage that’s sitting in your servers, unused and still consuming power, into a shared SAN.

Taking a look at storage processors, AMD and Intel are clearly leading the industry when it comes to developing technology that makes x86 processors more power efficient. According to Intel, their dual core architecture provides an 80% performance increase over existing Xeon processors while reducing power consumption by 35%. A few words from Intel’s CEO Paul Otellini describe it best:

"Today, for every dollar you spend on server hardware, you're spending 50 cents to cool and power that machine. By 2010, it goes up to 70 cents per dollar, so focusing on energy efficiency is becoming job one."

More processor cores means more processing or Watts per minute per job. This is driving server and storage consolidation, in turn significantly reducing power and space requirements (see table below).

In fact, all of LeftHand’s disk arrays now run on Intel multi-core processors. Our real industry advantage comes from the fact that LeftHand’s SAN/iQ is hardware agonistic, so we can bring advanced storage virtualization and management capabilities to the greenest storage platforms available.

LeftHand’s Storage Platforms also use the latest power-saving disk drive technology: reliable, inexpensive SAS drives, which consume less power and will, I believe, eventually replace all shared bus drive technology, including Parallel SCSI and Fibre Channel Arbitrated Loop. Typical power consumption for a Fibre Channel drive is 18.8 Watts, compared with 17.4 Watts for SAS drives based on disk drive specifications from the manufacturer. SAS drives also perform better – no shared SCSI buses, no arbitrated loop I/O contention, no more LIP storms or FC drive chatter – all dedicated, high speed point-to-point serial interconnects.

Last week we were competing with a Fibre Channel drive vendor who argued that “SAS drive technology limits scalability.” He clearly hadn’t done his homework. SAS technology allows you to connect up to 16,384 drives in a single system, and LeftHand’s clustering software is capable of connecting as many systems together as you need into a single pool - so much for that argument.Customers are smart, and they’re starting to figure out the truth.  And let’s not forget about iSCSI’s no-power-required software initiator instead of that that 6.5W HBA that needs to be installed in all your servers in order to connect to a Fibre Channel SAN.

So how can you find a solution that’s really green? Look for a storage solution that takes advantage of power savings from leading processor technology, provides low power consumption disk drive technology, and provides software that allows you to manage your storage efficiently and grow it as needed without disruption or rip-and-replace controller head upgrades.  That’s a green SAN.