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Design best practices
8 Dell EMC PowerVault ME4 Series and Microsoft Hyper-V | 3921-BP-WS
2 Design best practices
This section provides guidance on sizing and configuration options for ME4 Series storage and Hyper-V.
2.1 Right-size the storage array
Before deploying a new ME4 Series storage array, it is important to consider the environmental design factors
that impact storage capacity and performance so that new or expanded storage is right-sized for the
environment. If the ME4 Series array will be deployed to support an existing Hyper-V workload, metrics such
as storage capacity and I/O demands might already be understood. If the environment is new, these factors
need to be determined to correctly size the storage array.
Many common short- and long-term problems can be avoided by making sure the storage part of the solution
will provide the right capacity and performance in the present and future. Scalability is a key design
consideration. For example, Hyper-V clusters can start small with two nodes, and expand one node at a time,
up to a maximum of 64 nodes per cluster. Storage including ME4 Series arrays can start with a small number
of drives, and expand capacity and I/O performance over time by adding expansion enclosures with more
drives as workload demands increase.
Optimizing performance is a process of identifying and mitigating design limitations that cause bottlenecks —
the point at which performance begins to be impacted under load because a capacity threshold is reached
somewhere within the overall design. The goal is to maintain a balanced configuration that allows the
workload to operate at or near peak efficiency.
One common mistake made when sizing a storage array is assuming that total disk capacity translates to disk
performance. Installing a small number of large-capacity spinning drives in an array does not automatically
translate to high performance just because there is a lot of available storage capacity. There must be enough
of the right kind of drives to support the I/O demands of a workload in addition to raw storage capacity.
Where available, customers can confidently use the configuration guidance in Dell EMC storage reference
architecture white papers as good baselines to right-size their environments.
Work with your Dell EMC representative to complete a performance evaluation if there are questions about
right-sizing an ME4 Series storage solution for your environment and workload.
2.2 Linear and virtual disk groups, pools, and RAID configuration
Choosing the type of disk pools and RAID configurations to use is equally important to right-sizing the ME4
Series storage array for capacity and I/O.
The ME4 Series Administrator’s Guide provides an in-depth review and comparison of linear and virtual disk
groups, pools, the different RAID levels and hot spare configurations available with each, the trade-offs of
choosing one over the other, and application (workload) recommendations for each.
One option discussed in the Administrator’s Guide is the ME4 Series ADAPT option for RAID. ADAPT
supports distributed sparing for extremely fast rebuild times, and large-capacity disk groups of up to 128 total
drives. However, ADAPT requires a minimum of 12 drives to start with, and all disks must be of the same type
and be in the same tier.