What was the NS0-156 exam?
NS0-156 was the NetApp Certified Data Administrator exam for Clustered Data ONTAP, released in 2013 as the first NCDA covering NetApp’s scale-out cluster architecture. NetApp published practice material for it under the title “Exam NS0-156 clustered Data ONTAP Administrator.” The exam is retired, but the architecture it covered became the only ONTAP architecture, and the NCDA line continued through NS0-157 and NS0-160 to the current NS0-162.
You Certified on the Winning Side of a Genuine Fork
For several years NetApp shipped two fundamentally different architectures under the Data ONTAP name, and certified them separately. That is unusual, and it is the single most useful thing to understand about a NetApp credential from this period.
7-Mode, covered by NS0-155, was the traditional design: storage controllers deployed in high-availability pairs, each managed as its own system. It was mature, well understood, and had a very large installed base.
Clustered Data ONTAP, covered by this exam, was a scale-out design. Multiple controller pairs joined a single cluster with one management plane. Storage virtual machines, also called vservers, abstracted the logical serving of data away from the physical hardware, which meant volumes could move between nodes while remaining online and hardware could be replaced without an outage.
These were not versions of one another. They had different administration models, different command sets, and different capabilities, and NetApp maintained both in parallel because the installed base could not migrate overnight.
Clustered ONTAP won outright. 7-Mode was end-of-lifed, and once it was gone the qualifier became redundant, so the product became simply ONTAP from ONTAP 9 onward.
If you hold NS0-156, you certified on the architecture that became the entire product line.
What the Exam Covered
Clustered ONTAP administration centred on concepts that did not exist in 7-Mode:
Storage virtual machines. The core abstraction. An SVM owned volumes, logical interfaces, and its own namespace and authentication, and it was not tied to particular hardware. Multi-tenancy came from this, and so did most of the platform’s flexibility.
Logical interfaces. Network addresses belonged to the SVM rather than to a physical port, and could migrate between ports and nodes. Understanding LIF placement, failover groups, and the consequences for client connections was central and was one of the areas people most often got wrong.
Cluster networking. A dedicated cluster interconnect carried intra-cluster traffic, separate from data networking. Its health directly determined cluster stability.
Volume mobility. Moving a volume between aggregates or nodes while it stayed online was the headline capability, and it underpinned the non-disruptive operations argument that justified the whole architecture.
Aggregates, volumes, and qtrees, the storage layering, plus NFS and CIFS protocol configuration through the SVM.
Snapshots, SnapMirror, and SnapVault for point-in-time copies, replication, and backup, which were NetApp’s long-standing strengths and carried over from 7-Mode with changed mechanics.
Where the NCDA Line Went
The credential ran continuously through and beyond this exam. NS0-156 was followed by NS0-157, then NS0-160, and the current NCDA is granted through NS0-162, NetApp Certified Data Administrator, ONTAP.
The name shed “Clustered” along the way for the reason given above: there was no longer another mode to distinguish it from.
That continuity is genuinely useful. Your knowledge is of the same lineage as the current product, and the current exam is a real continuation rather than a different subject wearing a familiar name.
What This Knowledge Is Worth Today
As a current certification, it is expired, being tied to a superseded release, and the NCDA code has incremented several times since.
As foundational knowledge of current ONTAP, it holds up unusually well. The clustered architecture you learned is the architecture ONTAP still uses. SVMs, LIFs, volume mobility, and the aggregate and volume layering are all still how the product works.
What transferred:
Essentially all the architectural concepts. Someone who genuinely understood SVMs and LIF failover in 2014 can administer a current ONTAP system after learning what has been added, rather than relearning the model.
The storage efficiency and data protection story, deduplication, compression, snapshots, and SnapMirror replication, carried forward and remains central to the platform.
Non-disruptive operations thinking, designing so that maintenance does not require an outage, is a discipline that applies well beyond NetApp.
What was added since: substantial cloud integration, including ONTAP running in public cloud environments, plus newer efficiency features, and the management tooling moved on considerably from the interfaces of that era.
How to present it. Name the credential and note the version: “NetApp Certified Data Administrator (NCDA), Clustered Data ONTAP, 2014.” If you want the relevance to register with a reader who does not know the version history, saying that you certified on clustered ONTAP rather than 7-Mode communicates something real, since it places you on the surviving architecture.
Where the Path Leads
If you still administer NetApp, the current NCDA is the direct continuation and your foundation genuinely shortens the work. Verify the current exam code with NetApp directly, since it has changed several times.
If you moved to cloud storage, the concepts map more cleanly than you might expect. Storage virtual machines are a multi-tenancy abstraction of the kind cloud providers implement pervasively, and volume mobility without downtime is the same promise cloud block storage makes. ONTAP also runs in the major clouds, so the platform knowledge itself may still apply directly.
If you moved toward infrastructure architecture generally, the non-disruptive operations discipline is the transferable part, and it is a genuinely valuable habit of mind.
Frequently Asked Questions
Can I still take NS0-156? No. The exam is retired. The current NCDA is NS0-162, NetApp Certified Data Administrator, ONTAP.
What was the difference between NS0-155 and NS0-156? NS0-155 covered Data ONTAP 7-Mode, the traditional architecture of individually managed HA controller pairs. NS0-156 covered Clustered Data ONTAP, the scale-out architecture with storage virtual machines and volume mobility. They were genuinely different administration models.
Which architecture survived? Clustered ONTAP. 7-Mode was end-of-lifed, and from ONTAP 9 the product dropped the “Clustered” qualifier because no other mode remained.
What is a storage virtual machine? The core clustered ONTAP abstraction, also called a vserver. It owns volumes, logical interfaces, its own namespace and authentication, and is not tied to specific hardware, which is what enables multi-tenancy and non-disruptive data mobility.
Is my clustered ONTAP knowledge still relevant? Yes, substantially. SVMs, logical interfaces, volume mobility, and the aggregate and volume layering are still how current ONTAP works.
What is the current NCDA exam? NS0-162. The line ran NS0-156 to NS0-157 to NS0-160 to NS0-162.
References
NetApp. Exam NS0-156 clustered Data ONTAP Administrator. NetApp Learning Center practice material. https://learningcenter.netapp.com/content/public/production/extra/certification/NS0-156-PRACTICE/index_wbt.html (Primary source confirming the exam title and its clustered Data ONTAP administrator focus)
NetApp Community. NCDA NS0-160 / NS0-160i and NCDA: test NS0-155 or NS0-156? NetApp Learning Services Discussions. https://community.netapp.com/t5/NetApp-Learning-Services-Discussions/ (NetApp community sources for the NCDA exam succession, the 2013 release of NS0-156 as the first clustered ONTAP NCDA, and the deprecation of the 7-Mode exam)
NetApp. Certified Data Administrator Program. https://www.netapp.com/support-and-training/ (Current NCDA programme, granted through NS0-162)
NetApp. ONTAP. https://www.netapp.com/data-management/ontap-data-management-software/ (Current product, confirming the clustered architecture became the sole ONTAP architecture)