My presentation on software defined storage, presented at TECHunplugged Austin on 2 February 2016.

1. Software-Defined Storage
Fact or Fiction?
Austin, 2/2/2016Chris M Evans

2. Why Software is Eating The World
Expression coined by Marc
Andreessen, founder of
Netscape
2011 Essay in the Wall Street
Journal
http://www.wsj.com/articles/SB10001424053111903480904576512250915629460

3. What Does it Mean?
• Value is moving into software
(greater margins)
• Hardware is becoming more
commodity than ever (thinner
margins)
• Get out of the hardware business!
• Get into the software business!

4. What About Storage?
• Surely this can’t happen to
storage?
• Storage needs hardware, right?
• Storage will always be
delivered on hardware – won’t
it?

5. Storage Has Issues
• Exponential Growth
• Management Overhead
• Cost
• Agility
• Flexibility

6. Hyperscalers
• What do Google, Facebook and Amazon do?
• Surely they have cracked the storage
problem?
• Good question….

7. What Do Google Do (2009)?
http://www.cnet.com/news/google-uncloaks-once-secret-server-10209580/

8. Backblaze – Another Example

9. Google For the Data Centre?
• Google designs for small number of apps and millions
of users
• Redundancy built into the application
• Very read-centric architecture – lots of ability to cache
• Internet-based response times
• Home grown Software Defined Storage
• FREE!!

10. Private Data Centres are different
• Google/Facebook/Backblaze
architectures don’t directly
translate to the private data
centre
• Applications have specific SLAs
– Availability
– Performance
• Downtime = MONEY

11. Enter Software Defined Storage
• What could SDS and storage virtualisation give
us?
– Abstract away the hardware issues
– Use abstraction & software to automate
provisioning
– Opportunity to reduce costs

12. SDS Defined
• Wikipedia defines SDS as:
Software-defined storage (SDS) is an evolving concept for computer data
storage software to manage policy-based provisioning and management
of data storage independent of the underlying hardware.
• SNIA defines SDS as:
Virtualized storage with a service management interface. SDS includes
pools of storage with data service characteristics that may be applied to
meet the requirements specified through the service management
interface.
SDS as a term evolved from SDN, however SDN is fundamentally different
as networks don’t have to manage state.

13. SDS Key Features – My Definition
• Abstraction – I/O services should be delivered independent
of the underlying hardware, through logical constructs like
LUNs, volumes, file shares and repositories.
• Automation – resources should be consumed using CLIs
and APIs rather than manually allocated through a GUI.
• Policy/Service Driven – the service received (IOPS, latency)
should be established by policies that implement Quality of
Service, availability and resiliency.
• Scalable – solutions should enable performance & capacity
scaling independent of I/O delivery.

14. SDS – Commodity Hardware?
• Well, D’oh! Obviously!
• Vendors have been moving away from
bespoke hardware for many years
• Intel x86 deployed in EMC Symmetrix in
2009 – VMAX
– CLARiiON, Celerra, Centera all Intel Xeon
based in 2010
• Hitachi VSP was x86-based in 2011
• Compellent hardware was all commodity

15. Bespoke Hardware isn’t bad!
• 3PAR has had custom ASIC since inception and
still uses it to accelerate some functions
• SimpliVity has hardware-based de-duplication
• Server vendors (e.g. SuperMicro) are creating
storage-specific hardware – multi-node, high-
drive count systems
• Just don’t create a “Homer”…

16. Storage Virtualisation
• Abstracts the physical storage from the user through the use of logical
LUNs, volumes and shares
• Provides:
– Mobility – move physical data around without affecting logical view
– Flexibility – re-use existing resources effectively, extend life of legacy assets
– Efficiency – use virtualisation controller to implement data services
– Lower Cost – can be used to reduce cost of solutions with intelligent design
• Storage Virtualisation is 25 Years Old!
– First Integrated Cached Disk Array (ICDA) introduced by EMC in 1990
– Abstracted 5.25” drives as logical LUNs with RAID mirroring
– We’ve been abstracting data ever since!

17. Storage Virtualisation - Evolution
• Monolithic – single central controller
– Inline in the data path
– Controller maps logical to “physical” storage
– data management features built into the controller
– Not highly scalable
• Centralised Metadata – Distributed Data
– Central metadata functions
– Data distributed/replicated across many devices
– System not in the data path
– Separation of control and data planes
• Totally Distributed
– No central metadata or data
– Data distributed across many devices
– Fully scalable architecture

18. What Does SDS & Virtualisation let us do differently?
• Flexibility – let’s end users choose the whole
configuration – including hardware components
• Agility - easily introduce new features – simple
software upgrade to implement more efficient
dedupe, or support additional snapshots
• Efficiency - reuse old resources – sweat the
assets, move data around to the most effective
hardware based on price/performance
• Transparency – now we can see how much
markup vendors were making on the hardware
• Deliver Storage as a Service

19. But what’s the negative side?
• Vendors can’t test every hardware combination –
sometimes you will be on your own
• Performance profiles will be difficult to gauge unless
you test yourself
• There’s little or no shared experience – unlike analytics
an appliance vendor can do across all their customers
• SDS doesn’t necessarily fix issues of data migration,
data protection, etc (although storage virtualisation
helps)

20. Is Software Defined Storage for Me?
• Well it depends…
• Good Use Cases to dip your toe in the water
– ROBO/SMB – low cost branch deployments with
virtualisation
– Scale out archive – object or NAS
– Hyper-convergence

21. Who’s after your business?
• Storage industry is a huge growth area
• New businesses coming to market each year
• So who might be knocking on your door?
• Bring on the NASCAR slide….

23. So, is SDS Fact or Fiction
• SDS is FACT
• It is here today and has been with us for some
time
• The hard part now is deciding which vendor is
right for you and cutting through the
marketing hype

24. Further Reading
@chrismevans
https://blog.architecting.it
https://www.langtonblue.com