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Optimize Hyper-V for SC Series
14 Dell EMC SC Series: Microsoft Hyper-V Best Practices | CML1009
2.3.2 Virtual hard disk type
In addition to the format, a VHD can be designated as fixed, dynamically expanding, or differencing. Since SC
Series storage leverages thin provisioning, only the data that is written to a virtual hard disk, regardless of the
disk type, will consume space on the storage array. As a result, determining the best disk type is more a
function of workload requirements rather than how it will impact storage utilization on SC Series storage.
Select a virtual hard disk type
The dynamically expanding disk type will work well for most workloads. For workloads that generate very high
I/O, such as SQL Server databases, Microsoft recommends using the fixed size disk type.
As shown below, a fixed virtual hard disk consumes the full amount of space from the perspective of the host
server. For a dynamic virtual hard disk, the space consumed is equal to the amount of data on the virtual disk
(plus a little extra for metadata) and is therefore more space efficient from the perspective of the host. From
the perspective of the guest VM, either type of virtual hard disk will appear as a full 60 GB of available space.
Fixed and dynamic virtual hard disk comparison