Free and Premium EMC D-UN-DY-23 Dumps Questions Answers

A LUN is a logical unit of storage that is presented to a host as a SCSI device. A LUN is composed of one or more RAID extents, which are the smallest units of storage that can be allocated to a LUN. A RAID extent is a slice of a RAID group that is used to store user data and parity information. The size of a RAID extent depends on the RAID type and the drive type of the RAID group. For example, a RAID 5 extent on a SAS drive is 128 MB, while a RAID 6 extent on a NL-SAS drive is 256 MB. The LUN is partitioned into slices that match the size of the RAID extents, and each slice is mapped to a RAID extent from a RAID group in the storage pool. The LUN slices are distributed across multiple RAID groups to improve performance and availability. References:

Dell EMC Unity: Storage Pools and RAID Groups

Dell EMC Unity: LUN Management

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.

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 Lowest Priority. 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.

The correct sequence of steps to provision storage for SMB NAS clients is:

Group hard drives into storage pools. This allows you to create a pool of storage resources that can be allocated to different types of storage objects, such as NAS servers, file systems, and LUNs. You can create different pools based on the performance and capacity requirements of your applications1

Create a NAS server for an existing pool. A NAS server is a logical entity that provides file-level access to clients using SMB, NFS, or FTP/SFTP protocols. You need to create a NAS server before you can create file systems and shares. You can specify the pool, network settings, domain membership, and other properties for the NAS server2

Create file systems and file system shares based on the supported NAS protocol. A file system is a logical container that stores files and folders on a NAS server. A file system share is a logical representation of a file system that can be accessed by clients using a specific protocol. For SMB NAS clients, you need to create SMB file system shares that support the SMB protocol. You can configure the share name, permissions, access policies, and other settings for the SMB share3

Map the shared file system to the client. This allows the client to access the files and folders on the SMB share using a drive letter or a UNC path. You can use the Windows Explorer or the net use command to map the shared file system to the client4

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.

The Dell UnityVSA is a software-defined storage solution that runs the Dell Unity operating environment on a VMware ESXi server. The Dell UnityVSA provides the same features and functions as the Dell Unity hardware platform, such as block and file storage, snapshots, thin clones, data reduction, replication, and encryption. Some of the features of the Dell UnityVSA are:

iSCSI Connectivity: The Dell UnityVSA supports iSCSI connectivity for block storage access. The iSCSI protocol enables hosts to communicate with the Dell UnityVSA over an IP network and access LUNs as SCSI devices. The Dell UnityVSA can support up to 64 iSCSI interfaces and up to 256 iSCSI sessions per interface.

Asynchronous Replication: The Dell UnityVSA supports asynchronous replication for block and file storage. Asynchronous replication is a feature that copies data from a source storage resource to a destination storage resource over a network at scheduled intervals. Asynchronous replication can be used for disaster recovery, data migration, or backup purposes. The Dell UnityVSA can support up to 256 replication sessions per system.

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

When deploying Dell UnityVSA OVA, the recommended disk format is Thick Provision Eager Zeroed, which allocates and zeroes out all the space for the virtual disks at the time of creation. This ensures better performance and avoids potential issues with thin provisioning on the underlying storage. Thin Provision and Thick Provision Lazy Zeroed are not recommended, as they may cause performance degradation and unexpected out-of-space errors.

The service task that the administrator should perform to fix the issue with minimal impact is Restart Management Software. This service task restarts the management software on both storage processors without affecting the data services or the host I/O. This can resolve the communication issues between Unisphere and the storage system. Reinitialize, Enable SSH, and Reboot Storage Processor are service tasks that have more impact and risk than Restart Management Software.

To meet the requirements, the replication connection mode must be set to Both, which allows both synchronous and asynchronous replication sessions to be configured on the same connection. This way, block resources can use synchronous replication, which ensures zero data loss, and file resources can use asynchronous replication, which allows some data difference on the destination. Setting Unisphere resource filtering to All is not necessary, as it only affects the display of resources in the Unisphere GUI. Setting an RPO of 0 on the synchronous replication sessions is redundant, as synchronous replication always has an RPO of 0. Configuring the replication interfaces on the 4-port mezzanine card is not relevant, as it only affects the performance and availability of the replication network.

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.

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.