NS0-162 Exam Dumps : NetApp Certified Data Administrator (ONTAP)

The security method that would be used to authenticate targets and initiators in an ISCSI environment is CHAP. CHAP stands for Challenge Handshake Authentication Protocol, and it is a method that validates the identity of targets and initiators during the initial link. CHAP uses a shared secret (a password) that is exchanged between the target and the initiator in a challenge-response manner. CHAP can be used in both one-way and mutual modes, depending on whether both parties need to authenticate each other or not. The other options are not valid for this scenario because:

• NIS is a network information service that provides centralized management of user accounts and host names, but it does not provide authentication for ISCSI devices.
• LDAP is a protocol for accessing and managing directory services, such as user and group information, but it does not provide authentication for ISCSI devices.
• /etc/hosts is a file that maps host names to IP addresses, but it does not provide authentication for ISCSI devices. References :- How iSCSI authentication works, Securing iSCSI Devices, Configure iSCSI authentication

 To find the highest latency seen on restore, you need to look at the output of the table that shows the latency measurements for different operations and sizes. The highest latency is 10021 ms, which is the maximum latency for the GET operation with 8KB size. This means that when the users recover files with the Windows Previous Versions tab, they are reading data from the cloud tier that has been tiered using the snapshot-only policy, which causes high latency and slow restores.

• The other latencies are not correct, as they are lower than 10021 ms. The maximum latency for the PUT operation with 4MB size is 10500 ms, but this is not related to the restore operation, as it is writing data to the cloud tier. The maximum latency for the GET operation with 4KB size is 9591 ms, which is slightly lower than 10021 ms. The maximum latency for the GET operation with 32KB size is 7889 ms, which is much lower than 10021 ms. The maximum latency for the GET operation with 256KB size is 7838 ms, which is also much lower than 10021 ms. References :- FabricPool overview, FabricPool requirements, FabricPool best practices, High READ Latency from the fabric pool aggregate.

The space allocation option is a LUN attribute that enables the host to communicate with the storage system about the blocks that are no longer in use by the host file system. When the space allocation option is enabled, the host sends SCSI UNMAP commands to the storage system when files are deleted on the disk. The storage system then reclaims the space from the thin-provisioned LUN and makes it available for other LUNs or volumes. This process is also known as space reclamation or hole punching. If the space allocation option is disabled, the host does not send SCSI UNMAP commands and the storage system does not reclaim the space from the thin-provisioned LUN, resulting in a discrepancy between the host and the storage system. References :- Space reclamation, Enable or disable the space allocation option for a LUN