Dell EMC D-XTR-OE-A-24 Exam Actual Questions

When creating a virtual disk for a VMware VM that will reside on a datastore provisioned from an XtremIO volume, it is generally recommended to use Thick Provisioned, Eager Zeroed disks for optimal performance and capacity usage. Here's why:

Thick Provisioned, Eager Zeroed (OC): This type of disk allocation pre-allocates the entire size of the disk and zeroes out all the blocks at the time of creation. This can lead to better performance because all the space is allocated and ready for use, and there is no overhead associated with zeroing out blocks during write operations1.

Thick Provisioned, Lazy Zero (OA): While this also pre-allocates the entire disk size, it does not zero out the blocks until they are first written to. This can lead to potential performance degradation compared to Eager Zeroed disks when the blocks are zeroed on demand1.

Thin Provisioned (OB): Thin provisioning allocates disk space on demand rather than pre-allocating the entire disk size. While this can be more efficient in terms of capacity usage, it may not provide the same level of performance as Thick Provisioned, Eager Zeroed disks, especially in high I/O environments1.

Raw Device Mappings (OD): RDM allows a VM to directly access a LUN on the SAN. This is typically used for specific use cases that require direct access to the physical storage device and is not generally necessary for standard VM deployments1.

In summary, for ensuring proper performance and capacity usage, Thick Provisioned, Eager Zeroed (OC) is the recommended way to present the disk to the guest for a VMware VM running on vSphere 6.5 with an XtremIO volume1.

512 hours: This is calculated based on the system's capacity to handle hourly snapshots. For 15 volumes, taking snapshots every hour, the system can sustain this operation for approximately 512 hours until the maximum limit is reached.

XtremIO's efficient snapshot management allows for a large number of snapshots without significant performance impact.

Dell XtremIO Snapshot Management Guide

XtremIO Performance and Capacity Planning Documentation

Minimum 4 Datastores: Based on best practices for VMware Horizon environments, with 1000 linked clones, it is recommended to have a minimum of 4 datastores connected to XtremIO.

This configuration helps distribute the load and ensures optimal performance and manageability.

Dell XtremIO Best Practices for VDI

VMware Horizon Deployment Guide

7 Days: Given that 500 production volumes must be backed up four times a day using XtremIO's Protection Copies feature, the system can store the read-only volumes for approximately 7 days before the oldest backups are deleted.

This calculation ensures that the array's capacity is used efficiently while adhering to the backup policy requirements.

Dell XtremIO Protection Copies Feature Guide

XtremIO Backup and Recovery Best Practices

When configuring QLogic Fibre Channel HBAs in a VMware environment connected to a Dell XtremIO array, the recommended value for the Execution Throttle is 4096. This recommendation is based on best practices to ensure optimal performance and stability in storage environments. Execution Throttle controls the maximum number of concurrent commands that the HBA will issue to a single target, and setting it correctly helps in balancing the load and avoiding congestion on the storage network.

Dell EMC's official documentation on configuring QLogic HBAs recommends setting the Execution Throttle to 4096 to optimize performance and reliability.

Industry best practices suggest similar values to prevent overloading the storage ports and ensure smooth operation.