D-UN-DY-23 Sample Questions Answers

A Host Group is a logical grouping of hosts that share the same access permissions to storage objects, such as LUNs, VMFS Datastores, or NFS Filesystems. By configuring a Host Group, an administrator can simplify the management of multiple hosts and ensure consistent access to the storage resources. Some of the benefits of using a Host Group are:

• Provides multiple hosts access to the same VMFS Datastores: A VMFS Datastore is a block-based storage object that is formatted with the VMware File System (VMFS) and used to store virtual machine files. A VMFS Datastore can be shared by multiple hosts that are part of a VMware cluster. By adding these hosts to a Host Group and assigning the VMFS Datastore to the Host Group, the administrator can ensure that all the hosts have the same access permissions and can access the virtual machines on the Datastore.
• Provides multiple hosts access to the same LUNs: A LUN is a block-based storage object that is presented to a host as a SCSI device. A LUN can be shared by multiple hosts that have the same operating system and use a cluster-aware file system. By adding these hosts to a Host Group and assigning the LUN to the Host Group, the administrator can ensure that all the hosts have the same access permissions and can access the data on the LUN.

References:

• Dell EMC Unity: Host Configuration
• Dell EMC Unity: VMware ESXi Hosts and Clusters

To grant access of a Dell Unity XT provisioned NFS datastore to an ESXi host, the permission level required for the host depends on the NFS protocol and authentication method used by the NAS server. For NFSv4 with Kerberos NFS owner authentication, the ESXi host must have the Read/write, enable Root permission level. This allows the ESXi host to read and write data to the datastore, as well as perform administrative tasks such as creating and deleting virtual machines. The Read/write permission level alone is not sufficient, as it does not allow the ESXihost to perform root-level operations on the datastore. The Read-only permission level only allows the ESXi host to read data from the datastore, but not write or modify it. References: Dell EMC Unity: Configuring hosts to access NFS1, page 9.

The snapshot option that is set automatically when a pool is configured is the Pool Automatic Deletion Policy. This option determines how the system handles the deletion of snapshots when the pool reaches a certain threshold of capacity utilization. The user can choose between three policies: Never Delete, Delete Oldest, or Delete LowestPriority. The Total Pool Consumption and the Snapshot Pool Consumption are not snapshot options, but rather metrics that show the amount of pool space consumed by the pool data and the snapshots respectively.

References: [Dell EMC Unity: Storage Pools and RAID Groups], [Dell EMC Unity: Snapshots and Thin Clones]

If the time difference between the current system (UTC) time and the NTP server time is too large (approximately 17 minutes), the user cannot configure an NTP server during initial configuration. The user will need to adjust the time while in “Set time manually” mode before changing to “Enable NTP synchronization”. This is to avoid potential issues with data replication, snapshots, and audit logs that rely on accurate time stamps. References: Dell EMC Unity: How to change System Time from ‘Set time manually’ option to NTP2, page 1.

When the Schedule Time Zone is changed under the Settings menu, it only affects the display of the time zone and the creation of new snapshot schedules. Existing snapshot schedules are not automatically adjusted to the new time zone, and will continue to run at the same absolute time as before. For example, if a snapshot schedule was created to run every day at 10:00 AM inGMT+1, and the Schedule Time Zone was changed to GMT+2, the snapshot schedule will still run at 10:00 AM in GMT+1, which is 11:00 AM in GMT+2. To update the existing snapshot schedules to the new time zone, the administrator must edit each schedule manually and change the start time accordingly. References: Dell EMC Unity: Snapshots and Thin Clones1, page 16.

To apply the management IP from the vSphere UnityVSA console, the system administrator must use the svc_initial_config command. This command allows the user to configure the initial network settings for the UnityVSA, such as the management IP address, subnet mask, gateway, and DNS servers. The svc_ipmi command is used to configure the IPMI settings for the UnityVSA, such as the IPMI IP address, username, and password. The svc_change_hw_config command is used to change the hardware configuration of the UnityVSA, such as the number of CPU cores, memory size, and disk size. The svc_inject command is used to inject faults into the UnityVSA for testing purposes.

References: [Dell EMC UnityVSA Installation Guide], [Dell EMC UnityVSA Command Line Interface Reference Guide]

The Unity XT 680 system supports four types of I/O modules: 12 Gb/s SAS back-end, 4-Port 16 Gb Fibre Channel, 4-Port 25 Gbps Ethernet, and 4-Port 10 Gbps Ethernet. The 12 Gb/s SAS back-end module provides connectivity to the disk drives and expansion enclosures, while the other three types of modules provide network connectivity to the hosts and clients. The Unity XT 680 system has six I/O module slots, three for each SP. The 12 Gb/s SAS back-end module must be installed in slot 0 of each SP, and the other modules can be installed in slots 1 and 2 of each SP. Therefore, the correct answer is D. 12 Gb/s SAS back-end. References:

• Dell EMC Unity XT: Hardware Information Guide
• Dell EMC Unity XT: Installation Guide