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VDI test configuration
12 Dell EMC SC Series: 3,000 VMware Horizon Linked Clone VDI Users | 4735-RA-V
3 VDI test configuration
This section describes the VDI test configuration used for this document. There are many options for running
VDI workloads on SC Series hardware. A linked clone configuration was chosen due to the high adoption rate
among Dell EMC customers.
3.1 Block storage configuration
Block storage is used for this VDI deployment. NFS can be used for VM storage since ESXi supports NFS-
based datastores, but there was no benefit to using file-based storage for these tests.
3.1.1 Pools
The SC Series architecture is built around pools of disks. The system is designed to efficiently use all
available storage, without reserving disk storage for specific functions. All snapshots and volumes share the
entire pool of storage. This ensures storage capacity and performance are used as efficiently as possible. Any
new storage added is immediately available for volumes, replications, and snapshots.
The storage is intelligently striped at the page level to improve performance and efficiency. This is done
without user interaction. The system determines what data can be stored in a more efficient RAID type, and
what data requires high-performance RAID.
SC Series storage typically performs best with a single disk folder. This allows all volumes to share the
performance of all available drives, and makes the most efficient use of the space. If disk contention may be
an issue, QoS can be employed to control resource allocation, or multiple disk pools can be created.
A disk folder can contain disks of multiple tiers of performance and capacity. This enables data to be placed
on the most effective tier of storage, whether for best performance or cheapest capacity.
A single disk folder is created and the recommended storage profile is used. This is the configuration most
environments would use and provides the best performance in most scenarios.
3.1.2 Volumes
The volume size used is 4 TB. This allows VMs to grow as needed and VMware Horizon to detect the volume
space for VM growth. Horizon monitors drive capacity available and prevents VM placement on a volume that
it deems to be too full. This is a safety feature to prevent over-allocation to the point of failure. There are
settings to allow more aggressive VM placement, but these require administrators to closely monitor volume
utilization to ensure volumes do not fill up, or to have an automated process to grow volumes before they
reach capacity.
SC Series arrays can dynamically expand volumes quickly and easily if needed. This ability can prevent
Horizon from halting VM creation if a volume is approaching capacity.
3.1.3 VMware datastore
The VMFS 6 file system was used for all datastores. This is the default for VMware ESXi 6.7. The block size
was 1 MB. This allows Horizon to dynamically reclaim blocks as they are released from VMs. Automatic
space reclamations keep the volumes and disk pool from consuming excess space when VMs are torn down.