# Introduction to clustered Data ONTAP

## Iterative APIs

Iterative APIs allow you to operate on a large set of objects by dividing that set of objects into manageable sub-sets, repeatedly executing an API call.

To repeatedly call a Data ONTAP 7-Mode API, you can use *-iter-start, *-iter-next, and *-iter-end. In clustered environments, you can use a single API *-get-iter.

*-get-iter API supports queries, which can be used to return all objects that match the query. The objects are sorted alphabetically (default) in ascending order of the keys. It can be sorted numerically too.

Following are the input elements of an iterative API:

- max-records—determines the maximum objects that can be sent as response, in a one API call.

Each iterative API, for an API category, has a set upper limit and a default value. This element is supported for all APIs that support queries.

- tag— specifies a value used by the server to identify the next set of records to return.

If tag value is not specified, the server starts from the first record of the query result.

- query—specifies the query and must be specified for each iteration of an API.

You can use wildcards and range in a query.

- desired-attributes—specifies the number of elements that can be returned for each record.

This is an optional value. If it is not specified, elements, which contain values, are returned.

Following are the output elements of an iterative API:

- next-tag—specifies the tag value passed to the tag input element in the next call to the same API.

- num-records—specifies the total number of records returned for the API call.

- attributes-list—specifies the actual list of records in the *-get-iter API call.

Example of an iterative API

## Data ONTAP 7G-like API

Data ONTAP 8.1 and later provides APIs for both cluster and non-cluster nodes. Data ONTAP 7G-like APIs are APIs for non-cluster environment for those storage systems that have upgraded from Data ONTAP 7-Mode to clustered Data ONTAP. Upon upgrade, the storage system retains 7-Mode functionality, such as the IP address, and the cluster nodes can be accessed by using Storage Virtual Machine (SVM, formerly known as Vserver) tunneling mechanism.

You can find the list here.

## Data ONTAP White-list API

The Data ONTAP 7-Mode APIs that do not create, modify, or delete a cluster object are called Data ONTAP White-list APIs. A user in a cluster environment can use these 7-Mode API by using Storage Virtual Machine (SVM, formerly known as Vserver) tunneling.

You can find the list here.

## SVM tunneling

The mechanism of accessing 7G-like APIs to a Storage Virtual Machine (SVM, formerly known as Vserver) through a cluster-management interface is called SVM tunneling. This is for storage systems that have been upgraded from Data ONTAP 7-Mode to clustered Data ONTAP. If you want to access such a system, you have to use the Data ONTAP 7G-like API set.

Data ONTAP responds to a tunneled API based on the tunnel destination, target interface and the API family, as described in the following cases:

- Data ONTAP SVM APIs can be executed if they are sent through a cluster-management LIF to an Admin SVM.

- Data ONTAP SVM APIs can be executed if they are sent through a SVM-management LIF to a Data SVM.

- Data ONTAP SVM APIs can be executed if they are sent through a cluster-management LIF to a Data SVM.

- Data ONTAP clustered APIs can be executed if they are sent through a cluster-management LIF to a Node SVM.

##

## Network and File Access Management concepts

- Logical interface

  A logical interface (LIF) is an IP address with associated characteristics, such as a home port, a list of ports for failover, a firewall policy, a routing group. Logical interface is also known as virtual interface. For more information, see Data ONTAP documentation.

  Each logical interface has a role associated with it and must be assigned to the correct type of network port. A logical interface can have any one of the following four roles: node-management, cluster-management, cluster, or data.

- - Node-management

    A node-management logical interface provides a dedicated IP address for managing a particular node and is created at the time when a cluster is created or added to the cluster. Node-management logical interfaces can be configured on either node-management ports or data ports.

  - Cluster-management

    A cluster-management logical interface provides a single management interface for the entire cluster. Cluster-management logical interfaces can be configured only on data ports.

  - Cluster

    A cluster logical interface is used for intracluster traffic. Cluster logical interfaces can be configured only on cluster ports.

  - Data

    A data logical interface is used for communicating with clients. Data logical interfaces can be configured only on data ports.

- SVM

  In Data ONTAP C-Mode, a virtual server provides network access through unique network addresses, serves data out of a distinct namespace, and administered separately from the rest of the cluster. There are three types of SVMs: admin, data, and node. However, SVM usually refers to data SVM unless there is a specific need to identify different types of SVMs.

- - Admin SVM

    A SVM that has overall administrative access to all objects in the cluster, including the objects owned by other SVMs is an Admin SVM. It does not provide data access to clients or hosts.

  - Node SVM

    A SVM that is restricted to operation in a single node of the cluster at any one time, and provides administrative access to some objects owned by that node. It does not provide data access to clients or hosts.

  - Data SVM

    A virtual server that facilitates data access from the cluster; the hardware and storage resources of the cluster are dynamically shared by data SVMs within a cluster. Also known as a cluster SVM.

| To view information about role-based access on clustered Data ONTAP, see the System Administration Guide.

Related Topics

- List of Data ONTAP clustered APIs

- Clustered Data ONTAP System Administration Guide: NetApp Support Site