How to Use Iometer to Simulate a Desktop Workload
by: Jim Moyle
VDI Performance Testing: Mastering Iometer for Optimal Results
To deliver top-tier VDI Performance, understanding I/O performance is key when creating your VDI architecture. Iometer is widely treated as the industry-standard tool for testing load upon a storage subsystem. While many tools are available, Iometer’s balance between usability and function sets it apart. However, Iometer has its quirks, and this blog entry will show you exactly how to use it for the best results, especially when testing for VDI environments. We’ll also explain how to avoid being misled by flawed Iometer tests.
Understanding VDI I/O Profiles with Iometer
Since Iometer requires almost no infrastructure, you can use it to quickly determine storage subsystem performance. In a steady state, a desktop (VDI or RDS) I/O profile will be approximately 80% writes and 20% reads. It will also be 80% random and 20% sequential. Crucially, the block size of the reads and writes will typically be in 4KB blocks. While the block size in a real Windows workload varies between 512B and 1MB, the vast majority occur at 4KB. As Iometer does not allow a mixed block size during testing, we will use a constant 4KB.That said, while Iometer excels at analyzing storage subsystem performance, if you need to simulate a real-world workload for your VDI environment, I would recommend using tools from providers like Login VSI or DeNamik. These specialized tools provide a more comprehensive simulation for accurate VDI performance insights.