Defining Software Defined Storage (SDS), what it is, and isn’t.

Software Defined Storage (SDS) has become something of an overloaded term to mean many things these days.  This article is about how I see it being defined, what it is and isn’t.

Fundamentally, SDS is about a sea change that’s happening in the storage industry, it’s about providing companies with a way to plan for the future and to manage the reality of > 40% year-over-year data growth rates.  The key feature of SDS that makes managing this growth possible is the use of commodity-off-the-shelf (COTS) server hardware.  By moving beyond proprietary storage hardware, companies can take control over their largest component of IT spend, namely storage. Much like the migration from mainframes to open-systems took place over a decade ago, today a migration is happening from mainframe-like proprietary hardware storage systems to SDS appliances built using COTS hardware.  In my view this is the only way you can explain the flat growth of the leading traditional storage companies in this exponential data growth environment.

Don’t Believe the Hype

There are a lot of storage solutions out there under the banner of SDS but I’m going to make the argument that these are not all true SDS systems.  Here are a few signs the storage appliance you’re looking at may be traditional proprietary hardware under an SDS umbrella:

  • You’re being sold a system in a proprietary chassis or a white-box chassis with a custom bezel
    • Custom bezels look cool and there’s a lot of value to having the storage vendor constrain the hardware compatibility list to a narrow subset so that problems are easier to triage and solve. That’s great, but be careful that the fancy bezel doesn’t eliminate your ability negotiate the price of the hardware vs the price of the software or limit your ability to upgrade the system.
  • The price you’re paying on a per TB basis is equal to or higher than traditional Tier 1 systems.
    • If you’re cost per TB is not considerably lower you need to ask whether or not it is sustainable at this price and your data growth rate for the next 4-5 years let alone on into the future.
  • You have little to no ability to customize the hardware or software in the appliance such as adding more RAM, NICs, reporting software, etc
    • At OS NEXUS we get asked frequently can I add additional software or hardware to the system and because the platform is modular and Linux based usually the answer is often yes.  Just as you can add more RAM and NICs to your VMware servers you should have the flexibility to expand your storage appliances using approved commodity hardware when you need it.
  • The appliance APIs are not publicly available and/or are not REST APIs
    • If you can’t automate the appliance or if all they provide you with is antiquated SNMP, SMIS, or C/Java API interface that’s a red flag that indicates the vendor is selling rehashed legacy kit under an SDS banner.  Your appliances should be easily script-able with REST APIs and a solid CLI with XML output so you can fully automate common provisioning and configuration tasks.
  • The appliance has a completely proprietary IO stack / filesystem / volume manager
    • There’s no doubt plenty of room for great innovations in filesystems but they take a long time to mature (typically 10 years), and if the underlying filesystem is proprietary, you’re effectively locked in.  Great for the storage vendor, not so good for you.
  • The web interface looks like something from a circa ’99 DSL modem
    • You’ve got to maintain the box for the life of the data and that can be a long time.  When you have new engineers join your IT team you need to make sure the interface is intuitive and designed with good access controls.  Without that, your new IT staff can and inevitably will shoot themselves (and you) in the foot.

Taking a brief look at the state of IT today it’s clear that open-source-software (OSS) is king.  OpenStack, Hadoop, MongoDB, Gluster, Ceph, ZFS and many other open storage technologies are the tip of the spear of the cloud revolution.  It’s a market that demands a near zero-cost entry point with commercial support and management software for commercial deployments.  When you choose an SDS solution that’s built on open storage I/O stack you not only have a community behind it, you have an insurance policy that the technology will be there long into the future.

A Focus on OSS

This philosophy is central to what we do at OS NEXUS and is why the majority of our innovations are focused on our scale-out storage management layer and in making storage easy to manage.  For us it’s about making the best and most reliable SDS platform on the market by leveraging and integrating with the best enterprise OSS and commercial commodity hardware available.  We do that, package the SDS platform up as downloadable ISO image, and provide fanatical customer support so you have the peace-of-mind you need when you deploy and realize the benefits of SDS for your business.

Categories: Filesystems, Storage Appliance Hardware

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: