EMC Updated D-XTR-OE-A-24 Exam Questions and Answers by ana

The correct sequence of operations when a host writes a unique data block to an XtremIO X1 array is as follows:

Data is arranged into 8 KB blocks and fingerprinted.

Fingerprint to the physical array location mapping is created.

Location for the block on the array is selected.

Write operation is performed.

Reference count for the fingerprint is set to “1”.

Data Arrangement and Fingerprinting: Initially, the data received from the host is organized into 8 KB blocks.Each block is then fingerprinted, which involves creating a unique identifier for the data block that can be used to detect duplicates and manage data more efficiently1.

Mapping Creation: After fingerprinting, a mapping between the fingerprint and its physical location on the XtremIO array is established.This step is crucial for the array to know where each data block is stored and to retrieve it quickly when needed1.

Location Selection: The XtremIO system then selects the most appropriate location for the data block on the array.This decision is based on various factors, including space availability and optimization algorithms1.

Write Operation: Once the location is determined, the actual write operation takes place.The data block is written to the selected spot on the SSD within the array1.

Reference Count Setting: Finally, a reference count for the data block’s fingerprint is set to “1”. This indicates that there is currently one instance of this data block stored on the array.The reference count is used to manage data deduplication and ensure efficient storage utilization1.

When an XtremIO snapshot is taken of a production volume, it creates two snapshot entities.

These snapshots are identified as S1 and S2.

The creation of S1 and S2 ensures that the data consistency and integrity are maintained while providing a point-in-time copy of the production volume.

These snapshots can be used for various purposes such as backup, testing, or disaster recovery without impacting the performance of the production volume.

References:

Dell XtremIO Snapshots Guide

XtremIO Best Practices for Snapshot Management

Small, random workloads are best suited for high IOPS in a VDI (Virtual Desktop Infrastructure) environment.

Such workloads typically consist of numerous small I/O operations, which require a high number of IOPS to maintain performance.

XtremIO's architecture is optimized for handling small, random I/O patterns efficiently, making it ideal for this type of VDI workload.

References:

Dell XtremIO VDI Best Practices

Storage Performance Fundamentals