nerdexam
Network_Appliance

NS0-157 · Question #249

When a pNFS client is connected on a LIF on node 1 of a 4-node clustered Data ONTAP pNFS 4.1 vServer, and node 2 performs a storage takeover (SFO) of node 1, and LIFs fail over to node 3, which…

The correct answer is C. The pNFS redirects access to a LIF on node 2. In pNFS 4.1 with clustered Data ONTAP, a storage failover triggers layout recall so the client is redirected to the node that now owns the data, not the original node.

Network Configuration and Data Access

Question

When a pNFS client is connected on a LIF on node 1 of a 4-node clustered Data ONTAP pNFS 4.1 vServer, and node 2 performs a storage takeover (SFO) of node 1, and LIFs fail over to node 3, which statement is true?

Options

  • AThis mount goes stale.
  • BThe client waits for node 1 to come back up.
  • CThe pNFS redirects access to a LIF on node 2.
  • DThe client accesses the virtual IP of the cluster which handles access to the data during the

How the community answered

(52 responses)
  • A
    13% (7)
  • B
    23% (12)
  • C
    56% (29)
  • D
    8% (4)

Why each option

In pNFS 4.1 with clustered Data ONTAP, a storage failover triggers layout recall so the client is redirected to the node that now owns the data, not the original node.

AThis mount goes stale.

pNFS 4.1 with clustered ONTAP is explicitly designed to survive storage failover transparently through layout recall, so the mount does not go stale.

BThe client waits for node 1 to come back up.

The pNFS client does not block and wait for the original node to return - the protocol actively redirects the client to the takeover node.

CThe pNFS redirects access to a LIF on node 2.Correct

When node 2 performs an SFO takeover of node 1, node 2 becomes the new owner of node 1's aggregates and volumes. The pNFS protocol uses layout recall and re-delegation mechanisms so the metadata server directs the client to a LIF on node 2, which now hosts the data. This ensures transparent continued access without the mount going stale or requiring client intervention.

DThe client accesses the virtual IP of the cluster which handles access to the data during the

Clustered Data ONTAP pNFS does not use a cluster-wide virtual IP for data redirection; it redirects to a specific LIF on the node that now owns the storage.

Concept tested: pNFS client behavior during storage failover

Source: https://docs.netapp.com/us-en/ontap/nfs-admin/ontap-support-nfsv4-concept.html

Topics

#pNFS 4.1#storage failover#LIF failover#NFS redirect

Community Discussion

No community discussion yet for this question.

Sign up to join the discussion
Full NS0-157 Practice