404 Implementing the IBM Storwize V7000 with IBM Spectrum Virtualize V8.2.1
10.1  Easy Tier
IBM Spectrum Virtualize includes the IBM System Storage Easy Tier function. It enables 
automated subvolume data placement throughout different storage tiers, and automatically 
moves extents within the same storage tier to intelligently align the system with current 
workload requirements. It also optimizes the use of Flash drives or flash arrays.
Many applications exhibit a significant skew in the distribution of I/O workload: a small fraction 
of the storage is responsible for a disproportionately large fraction of the total I/O workload of 
an environment. 
Easy Tier acts to identify this skew and to automatically place data to take advantage of it. By 
moving the “hottest” data onto the fastest tier of storage, the workload on the remainder of the 
storage is significantly reduced. By servicing most of the application workload from the fastest 
storage, Easy Tier acts to accelerate application performance, and increase overall server 
utilization. This can reduce costs in servers and application licenses. 
10.1.1  Easy Tier concepts
Easy Tier is a performance optimization function that automatically migrates (or moves) 
extents that belong to a volume between different storage tiers, based on their I/O load. 
Movement of the extents is online and unnoticed from the host point of view. As a result of 
extent movement, the volume no longer has all its data in one tier, but rather in two or three 
tiers, and each tier provides optimal performance for the extent, as shown in Figure 10-1. 
Figure 10-1   Easy Tier
Easy Tier monitors the I/O activity and latency of the extents on all Easy Tier enabled storage 
pools. Based on the performance log, it creates an extent migration plan and promotes 
(moves) high activity or hot extents to a higher disk tier within the same storage pool. It also 
demotes extents whose activity dropped off, or cooled, by moving them from a higher disk tier 
MDisk back to a lower tier MDisk. 
Note: Easy Tier is a licensed function, but it is included in base code. No actions are 
required to activate the Easy Tier license on IBM Storwize V7000.