Monitoring capabilities for Virtual and Physical Raw Device Mappings (RDMs) in VMware Aria Operations

Products

• VCF Operations

Issue/Introduction

This article provides clarification regarding VMware Aria Operations capabilities for monitoring performance and capacity metrics on Raw Device Mappings (RDMs). Telemetry collection varies significantly depending on the compatibility mode (Virtual or Physical).

• Performance metrics (Latency, IOPS, Throughput) are missing for certain Virtual Machines.
• Physical RDM disks do not show deep storage telemetry in the vCenter adapter.

Environment

• Aria Operations 8.18.x
• vCenter 7.x and 8.x

Cause

Physical Compatibility Mode (pRDM) allows the guest operating system to send raw SCSI commands directly to the storage hardware, bypassing the ESXi storage virtualization layer where native vCenter metrics are captured.

Resolution

Follow the guidelines below based on the RDM compatibility mode:

1. Virtual Compatibility Mode (vRDM)
   • No additional action is required. ESXi intercepts I/O.
   • Aria Operations natively collects standard Virtual Disk metrics (Read/Write Latency, IOPS, Throughput) via the vCenter adapter.
2. Physical Compatibility Mode (pRDM) Performance
   • Note that Aria Operations cannot natively monitor performance (Latency, IOPS, Throughput) of pRDMs via the vCenter adapter.
   • To obtain hardware-level metrics, deploy a specific Storage Vendor Management Pack (e.g., Pure Storage, Dell EMC, NetApp).
3. Physical Compatibility Mode (pRDM) Capacity
   • Ensure VMware Tools is running in the guest OS.
   • Metrics (Total Capacity, Used Space, Free Space) will populate under the "Guest File System" metric group for the Virtual Machine object.

Additional Information

 

• RDM Virtual and Physical Compatibility Modes

• Aria Operations Metrics (Virtual Machine and Datastore)

• Aria Operations Telegraf Agent Configuration