D-UN-DY-23 Dell Unity Deploy 2023 Exam Questions and Answers

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

https://www.delltechnologies.com/asset/en-us/products/storage/industry-market/h15089-dell_emc_unity-snapshots_and_thin_clones.pdf

A feature that can be configured for a Dell Unity XT file system NFS share is the Host Access Level. This feature allows the user to specify the access permissions for each host or host group that is allowed to access the NFS share. The access permissions can be set to Read/Write, Read Only, or No Access. The Host Access Level feature can be used to control the security and performance of the NFS share. Access-Based Enumeration, Protocol Encryption, and Distributed File System are features that can be configured for a Dell Unity XT file system SMB share, not NFS share.

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 in GMT+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.

The maximum number of drives on a traditional RAID group depends on the RAID type and the drive type. For RAID 5 and RAID 6, the maximum number of drives is 16 for all drive types. For RAID 1/0, the maximum number of drives is 32 for SAS and NL-SAS drives, and 16 for SSD drives. References: Dell EMC Unity: Best Practices Guide2, page 17.

To expand a dynamic pool, the number of drives added must be equal to or greater than the stripe width of the pool. The stripe width is the number of data drives plus the number of parity drives in a RAID group. In this case, the stripe width is 12 + 1 = 13. Therefore, the minimum number of drives needed for the pool expansion is 13. References: Dell EMC Unity: Dynamic Pools Technical White Paper1, page 8.

The firewall ports that are required to be open for a successful outbound connection when configuring integrated secure connect gateway are 443 and 8443. Integrated secure connect gateway is a feature that enables secure remote access to the Dell Unity system through the Unisphere Central web portal. It requires an outbound connection from the Dell Unity system to the Unisphere Central server over the internet. Port 443 is used for HTTPS communication and port 8443 is used for WebSocket communication.