NS0-162 Exam Dumps - Netapp Certified Data Administrator (NCDA) Questions and Answers

The NetApp solution that fulfills the requirements is SnapMirror Business Continuity (SM-BC). SM-BC is a business continuity solution for zero RPO and near zero RTO that was introduced in ONTAP 9.8. SM-BC enables transparent application failover and failback between two ONTAP clusters without requiring any application reconfiguration. SM-BC supports ISCSI LUNs as well as NFS and SMB file shares. The other options are not suitable for this scenario because:

• SyncMirror is a local high availability solution that mirrors data within a single HA pair, not across clusters.
• SVM DR is a disaster recovery solution that replicates data and configuration of an SVM to another cluster, but requires manual intervention to activate the destination SVM and reconfigure the application.
• SMS is a synchronous replication solution that provides zero RPO, but not zero RTO, as it also requires manual intervention to activate the destination volume and reconfigure the application. References :- SnapMirror Business Continuity overview, SnapMirror Business Continuity for ONTAP 9.12, SnapMirror Business Continuity FAQ

Encrypted volumes are one of the possible causes of ONTAP upgrade pre-check failure. If the cluster has encrypted volumes, the pre-check verifies that the cluster has a valid external key manager (EKM) configuration and that the EKM server is reachable. If the EKM configuration is invalid or the EKM server is unreachable, the pre-check fails and the upgrade cannot proceed. To resolve this issue, the cluster administrator must ensure that the EKM configuration is correct and that the EKM server is accessible before retrying the upgrade12. References:- Execute ONTAP automated pre-upgrade checks before a planned upgrade, ONTAP upgrade pre-check validation fails with Error: The following nodes are not supported

Storage efficiency features are techniques that reduce the amount of physical storage required to store data. ONTAP supports various storage efficiency features, such as deduplication, compression, and compaction. On AFF systems, some of these features are enabled by default on all newly created volumes. According to the documentation1, the following storage efficiency features are enabled by default on AFF systems:

• Aggregate-level compression: This feature compresses data blocks at the aggregate level, reducing the physical space required to store data. Aggregate-level compression is applied after all other storage efficiency features, such as deduplication and compaction, are applied at the volume level. Aggregate-level compression is enabled by default on all aggregates on AFF systems.
• Volume-level inline deduplication: This feature eliminates duplicate data blocks within a volume before they are written to disk, reducing the amount of data written and improving performance. Volume-level inline deduplication is enabled by default on all volumes on AFF systems.

Other storage efficiency features, such as LUN-level compression and aggregate-level inline deduplication, are not enabled by default on AFF systems. LUN-level compression is a feature that compresses data blocks at the LUN level, reducing the logical space required to store data. LUN-level compression is disabled by default on all LUNs on AFF systems, and it is not recommended to enable it unless there is a specific use case. Aggregate-level inline deduplication is a feature that eliminates duplicate data blocks across volumes within an aggregate before they are written to disk, reducing the amount of data written and improving performance. Aggregate-level inline deduplication is disabled by default on all aggregates on AFF systems, and it is recommended to enable it only on aggregates that contain volumes with similar data sets. References :- Inline storage efficiency enabled by default on AFF systems, Storage efficiency features, LUN-level compression, Aggregate-level inline deduplication

 The action that you should take to ensure that the LIF only fails over to the correct ports is to change the LIF’s failover policy to sfo-partner-only. This failover policy restricts the target ports to the home node and its storage failover (SFO) partner only, excluding any other nodes in the cluster. This way, the LIF will only fail over to port eOc or eOd on either storage node, as shown in the exhibit. The other options are not valid for this scenario because:

• Creating a DNS load balancing zone does not affect the LIF failover behavior, but rather provides a way to distribute client requests across multiple LIFs using DNS round-robin.
• Splitting the broadcast domain does not ensure that the LIF only fails over to the correct ports, but rather creates separate groups of ports that are on the same Ethernet broadcast domain. This may affect the LIF reachability and performance.
• Creating an IPspace does not ensure that the LIF only fails over to the correct ports, but rather isolates network traffic for a set of SVMs within a cluster. This may affect the LIF connectivity and security. References :- Network interface failover policies - behavior and uses, Configure failover settings on a LIF, storage failover takeover

NVMe is a protocol that enables fast and efficient access to storage devices over a network. NVMe uses NVM Express over Fabrics (NVMe-oF) to transport commands and data between hosts and storage systems. NVMe-oF uses NVM subsystems, which are logical containers for one or more NVMe namespaces. A namespace is a logical unit of storage that can be accessed by a host. A host can discover and connect to an NVM subsystem by using a unique NVM subsystem identifier (NQN). ONTAP supports NVMe/FC and NVMe/RoCE as the transport protocols for NVMe-oF. ONTAP maps NVMe namespaces to LUNs and NQNs to subsystems. ONTAP also maps initiator groups to subsystems to control host access to namespaces. References :- NVMe Overview, Implementing and Configuring Modern SANs with NVMe/FC, NVMe-oF host configuration for RHEL 8.9 with ONTAP

 NetApp ONTAP Select is a software-only version of ONTAP that can run on commodity servers with direct-attached storage. It supports both block and file protocols, including NFS, NVMe, and CIFS. SCSI and FCP are not supported by ONTAP Select. References :- ONTAP Select overview, Client protocols, Software-Defined Storage with ONTAP Select

 To troubleshoot the issue of iSCSI LUNs not visible on the host, you should verify that the iSCSI data protocol has been enabled on the ports and that the controller has not been taken over. If the iSCSI data protocol is disabled on the ports, the storage system will not accept iSCSI connections or requests over those ports. If the controller has been taken over by its partner, the iSCSI LUNs on the taken-over node will not be available to the host. You can use the vserver iscsi connection show command to check the status of the iSCSI connections and the storage failover show command to check the status of the controller. References :- Troubleshoot iSCSI LUNs not visible on the host, vserver iscsi connection show, storage failover show

 The broadcast-domain split command allows you to create a new broadcast domain by moving one or more ports from an existing broadcast domain to the new one. In this scenario, you can use this command to move the e0e and e0c ports from the Default broadcast domain to a new broadcast domain in the same IPspace. This would satisfy the requirement of creating a new broadcast domain with the specified ports. The other options are not valid for this scenario, as they either create a new broadcast domain without moving any ports (A), merge two existing broadcast domains into one (D), or require a graphical user interface ©. References :- network port broadcast-domain split, Create a broadcast domain

SnapDiff is an internal ONTAP engine that quickly identifies the file and directory differences between two Snapshot copies. SnapDiff can be used by backup applications to perform incremental backups, by reducing the amount of data that needs to be scanned and transferred. SnapDiff can also be used by other ONTAP features, such as SnapMirror and SnapVault, to optimize data replication and protection. References :- How incremental tape backup uses SnapDiff and Snapshot copies, Commvault Adds Features to Fortify Ransomware Security, Rubrik | Better NAS Backup RPO with Changelist Snapshots, Snapshot copies

To cache on-premises ONTAP volumes into the cloud with Cloud Volumes ONTAP, you need to use the FlexCache feature, which creates a writable, persistent cache of a data volume that is consistent and coherent with its original data set and stored in a remote location. FlexCache supports both SMB and NFS protocols, which are the traditional file access protocols for Windows and UNIX/Linux systems respectively. You can control file access using UNIX-style permissions, NTFS-style permissions, or a mix of both. Clients can access the same files using both SMB and NFS protocols123.

• NVMe and iSCSI are not supported by FlexCache, as they are block protocols that run on standard Ethernet networks. FlexCache is a file-based solution that works with file protocols only12. References :- Client protocols | NetApp Documentation, Client protocols - NetApp, Cloud Volumes ONTAP for AWS: Storage for the Cloud Era.