What is an advantage of sub-LUN tiering?

A.
Improved performance

B.
Enhanced reliability and availability

C.
Dynamic expansion of storage capacity

D.
Faster provisioning of thin LUNs

Explanation:
Intra-array Storage Tiering

The process of storage tiering within a storage array is called intra-array storage tiering. It enables
the efficient use of SSD, FC, and SATA drives within an array and provides performance and cost
optimization. The goal is to keep the SSDs busy by storing the most frequently accessed data on
them, while moving out the less frequently accessed data to the SATA drives. Data movements
executed between tiers can be performed at the LUN level or at the sub-LUN level. The
performance can be further improved by implementing tiered cache.
Traditionally, storage tiering is operated at the LUN level that moves an entire LUN from one tier of
storage to another. This movement includes both active and inactive data in that LUN.
This method does not give effective cost and performance benefits. Today, storage tiering can be
implemented at the sub-LUN level. In sub-LUN level tiering, a LUN is broken down into smaller
segments and tiered at that level. Movement of data with much finer granularity, for example 8
MB, greatly enhances the value proposition of automated storage tiering. Tiering at the sub-LUN
level effectively moves active data to faster drives and less active data to slower drives.
EMC E10-001 Student Resource Guide. Module 15: Managing the Storage Infrastructure