VDI test toolsLogin VSI
Login VSI by Login Consultants is the industry-standard tool for testing VDI environments and server-based computing (RDSH environments). It installs a standard collection of desktop application software (such as Microsoft Office and Adobe Acrobat Reader) on each VDI desktop; it then uses launcher systems to connect a specified number of users to available desktops within the environment. Once the user is connected, the workload is started using a logon script, which starts the test script once the user environment is configured by the login script. Each launcher system can launch connections to several ‘target’ machines (for example, VDI desktops).
VDI test methodology
To ensure the optimal combination of end-user experience (EUE) and cost-per-user, performance analysis and characterization (PAAC) on Dell Technologies VDI solutions is carried out using a carefully designed, holistic methodology that monitors both hardware resource utilization parameters and EUE during load-testing.
Login VSI can be used to determine the maximum number of desktops that can be run on a physical or virtual server. Login VSI simulates a realistic VDI workload using the Auto IT script within each desktop session to automate the execution of generic applications such as Microsoft Office 365, Internet Explorer, Acrobat Reader, Notepad, and other software.
The launchers and Login VSI environment are configured and managed by a centralized management console. Additionally, the following login and boot paradigm is used:
- Users are logged in within a login timeframe of 1 hour.
- All desktops are pre-booted before logins start.
Profiles and workloads
It is important to understand user workloads and profiles when designing a desktop virtualization solution and to understand the density numbers that the solution can support. At Dell Technologies, we use Task Worker and Knowledge Worker workload/profile levels, each of which is bound by specific metrics and capabilities to run different use cases. This is how we define profile and workload:
- Profile—The configuration of the virtual desktop. It relates to the number of vCPUs and the amount of RAM configured on the desktop that is available to the user.
- Workload—The set of applications that are used by performance analysis and characterization (PAAC) of Dell VDI solutions (for example, Microsoft Office applications, PDF Reader, Internet Explorer, and so on).
Load-testing on each profile is carried out using an appropriate workload that is representative of the relevant use case. The following table shows the load-testing that we used:
|Login VSI workload name||Workload description|
|Task Worker||A light workload that runs fewer applications and starts/stops them less frequently than the other workloads, resulting in lower CPU, RAM, and IO usage. The Task Worker workload uses the following applications:|
|Knowledge Worker||Designed for virtual machines with 2 vCPUs. This workload includes the following activities:|
The following sections explain the component monitoring that is used on Dell Technologies solutions.Logman
Logman is a command line utility that is built into Windows Server for performance monitoring and data collection. It helps to monitor and gather data from multiple servers. A config file to be created with the necessary performance counters and Logman can be used to build a data collector. This data collector can be run from the Logman CLI to gather data which eventually generates a CSV file with the data.Performance history for Storage Spaces Direct cluster volumes
We used the performance history feature in Storage Spaces Direct to monitor and gather different metrics such as network traffic, IOPS and disk latency. The cmdlets that we used to gather these metrics were
The purpose of this test was to determine the user density at a reasonable system load. Testing to system failure was out of scope. To achieve a reasonable system load, target thresholds for system resources were set as shown in the following table. These thresholds reflect a system that is well utilized, but not near failure.
|Hyper-V logical processor utilization||85%|
|Average memory utilization (active)||85%|
|Disk latency||20 milliseconds (ms)|
Test configuration details
The following table describes the hardware and software components of the infrastructure that was used for the PAAC test.
Compute host hardware
3 x AX-750 AS HCI nodes:
Windows Admin Center
BOSS-S2 (Embedded) controller
Dell HBA355i (Embedded)
All host machines were updated with the latest operating system and security updates
Desktop operating system
Microsoft Windows 10 Enterprise 64-Bit (version 21H2)
Microsoft Windows 10 Enterprise multisession (version 21H2)
Microsoft Office 365
Management operating system
Microsoft Azure Stack HCI (version 21H2)
Login VSI version
Windows was configured to automatically download and install updates. In addition to this, the sconfig command which is built into AS-HCI OS was used to ensure that the system was up to date and no security patches were missing.User VM configurations
The following table summarizes the standard PAAC VM configurations that are currently used for the various profiles/workloads tested.
The Windows 10 Multisession virtual machines had Microsoft Office 2019 installed and Windows 10 single session virtual machines had Office 365 Apps for Enterprise installed.
|Startup memory||Minimum RAM||Maximum RAM||Memory buffer||Operating system||Estimated density (per compute node)|
|Task Worker||32 GB||32 GB||32 GB||20%||Windows 10 Enterprise 64-bit Multisession||14|
|Knowledge Worker||4 GB||2 GB||4 GB||20%||Windows 10 Enterprise 64-bit, 21H2||290|