D-UN-DY-23 Practice Exam Questions with Answers Dell Unity Deploy 2023 Exam Certification

 Mixing FC and iSCSI protocols for the same host and array is not supported by Dell EMC Unity. This can cause issues with multipathing, failover, and performance. The best practice is to use one protocol per host and array pair. If the host needs to access both FC and iSCSI LUNs from different arrays, then separate vSwitches and port groups should be used for each protocol. References: Dell EMC Unity: Best Practices Guide1, page 19.

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.

A benefit of using vVols is that individual VMs on a datastore can be snapped. vVols are virtual volumes that are stored on a storage array and managed by vSphere. They enable granular control and management of VM storage. With vVols, each VM has its own set of virtual disks that are mapped to corresponding storage objects on the array. This allows the array to perform snapshot operations on individual VMs without affecting other VMs on the same datastore.

References: [Dell EMC Unity: VMware vSphere Virtual Volumes (vVols) Implementation]

Data Reduction is a feature that reduces the amount of physical storage space required to store user data on a LUN. Data Reduction is enabled at the LUN level and applies to all the data in the LUN, including snapshots and thin clones. Data Reduction consists of two components: compression and deduplication. Compression reduces the size of data blocks by removing redundant information, while deduplication eliminates duplicate blocks across the LUN. When Data Reduction is enabled on a LUN, all writes to the LUN will go through the Data Reduction logic before being written to the storage pool. If the LUN is part of a consistency group, Data Reduction will be enabled on all the LUNs in the consistency group, and all writes to any LUN in the group will go through the Data Reduction logic. This ensures that the data in the consistency group is consistent and protected by the same Data Reduction settings. References:

• Dell EMC Unity: Data Reduction Overview
• Dell EMC Unity: Data Reduction Configuration and Best Practices

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.