D-UN-DY-23 Exam Dumps : Dell Unity Deploy 2023 Exam

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

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.

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.