EMC D-UN-DY-23 Exam With Confidence Using Practice Dumps

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.

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 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 DellUnityVSA 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.

References:

• Dell EMC Unity: Introduction to the Platform
• Dell EMC Unity: Deploying VMware vSphere with Dell EMC UnityVSA
• Dell EMC Unity: Configuring Hosts to Access Block Storage
• Dell EMC Unity: Replication Technologies