White Papers

Optimize Hyper-V for SC Series
22 Dell EMC SC Series: Microsoft Hyper-V Best Practices | CML1009
feature enhancements offered with newer releases of Hyper-V (generation 2 guest VMs, VHDX format, and
shared VHDs in Windows Server 2016 Hyper-V and newer). Use cases for pass-through disks are like those
for direct-attached storage (see section 2.8).
Although SC Series Replay Manager supports protecting pass-through disks, use of in-guest iSCSI is
recommended, since in-guest iSCSI is required to perform a recovery. See the
Dell EMC SC Series Replay
Manager for Hyper-V best practice guide for more information.
Limitations when using pass-through disks includes the list in section 2.8 for direct-attached storage, along
with the following:
• Support for differencing disks is lost: The use of a pass-through disk as a boot volume on a guest
VM prevents the use of a differencing disk. However, SC Series View Volumes (created from a gold
image volume) can still be used to maximizing SAN space utilization.
• Difficult to manage: The use of pass-through disks becomes unmanageable and impractical at
larger scale.
• LUN number limits: In large environments with a high number of cluster nodes and guests, it is
possible to exhaust the pool of available LUN numbers on your hosts when using pass-through disks.
Cluster server objects on a Dell SC Series support a maximum of 254 LUNs. Avoid this limitation by
using direct-attached disks. See section 2.11 for more details.
2.10 SC Series arrays and cluster server objects
When mapping shared SC Series volumes (quorum disks, cluster disks, or cluster shared volumes) to
multiple Hyper-V nodes, make sure that the volume is mapped to all nodes in the cluster using a consistent
LUN number.
Leverage cluster server objects on the SC Series array to simplify the task of mapping a new volume to many
nodes at the same time. This can be a significant time saver in larger environments and can help reduce the
risk of user error.
Note: The use of SC Series cluster server objects is not supported when a guest VM cluster is configured to
use vFC adapters.
Some advantages of using SC Series cluster server objects include the following:
• Fast: A new volume is mapped to all nodes in the cluster in one operation.
• Consistent: The volume is mapped to each node using a consistent LUN number.
• Accurate: Reduces the chance of user error or inconsistences when mapping volumes.
• Efficient: Saves time, particularly as the number of nodes and volumes increases. For example,
existing cluster volumes are automatically mapped to new cluster node when a new node is added to
the SC Series cluster object.