Clustered volumes and namespaces – DATA ONTAP C – Mode

Clustered volumes and namespaces – DATA ONTAP C – Mode

A junction joins together two flexible volumes in the same SVM. A junction in a parent flexible volume redirects client requests to a child flexible volume. A flexible volume must be junctioned into an SVM’s namespace for clients to access it.

A junction is nothing about UNIX mount point, where a directory serves as an entry point to another file system.

Junction differs from NFS automounters  and client side mounts in several respects:

  • Junctions allow the non-disruptive movement of a flexible volume from one physical node to another while preserving client connectivity, NetApp Snapshot copies, and replication relationships.
  • Junction require no client-side configuration or automount map
  • Junctions allow multiple flexible volumes under a singe NFS v3 export, reducing the number of mounts used by the client
  • Junctions are centrally managed in the DATA ONTAP cluster
  • File permissions on a junction path are not controlled by clients. They are controlled using the permissions of the flexible volumes that exists at the junction path


No file or directory can exist in the full path to be used for the junction, but the parent directory containing the junction must exist before the junction is created.For example, if an administrator wants to junction a flexible volumeinto the namespace at /x/y/z,there must be a directory or junction at /x/y but there cannot be an existing file, directory, or junction at /x/y/z.

An SVM’s top-level flexible volume is known as the SVM root volume.The SVMroot volume forms the root of the flexible volume hierarchy in anSVM.It is theparent, grandparent, or ancestor of every flexible volumein the SVM’s namespace.

A junction can exist beneath any directory in a parent flexible volume. A flexible volume can be junctioned to the namespace in only one location.This prevents the same flexible volumefrom appearing more than once in the namespace.

Junctions are implemented as a file system entry in the parent flexible volume. Information about the physical location of the child flexible volume is maintained by the cluster. If an administrator moves the child flexible volumeto a different aggregate inside the cluster, the cluster sends client traffic to the new location automatically. Clustered volumes and namespaces Clustered volumes and namespaces  Clustered volumes and namespaces  Clustered volumes and namespaces Clustered volumes and namespaces

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Thanks for your wonderful Support and Encouragement

Ankam Ravi Kumar

Working as Linux / Storage Administrator L3. Interested in sharing the knowledge.

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