# Check the disk controller before interpreting missing Azure latency metrics

> Does an absent Azure disk-latency series mean an NVMe-backed workload has no latency?

- Canonical URL: https://update.dsesecurity.com/updates/dse-20260909-054-check-the-disk-controller-before-interpreting-missing-azure-latency-metrics/
- Publisher: Detection Systems & Engineering (DSE Security)
- Author: DSE Security Editorial Team
- Published: 2026-09-10T00:31:02+00:00
- Modified: 2026-09-10T00:35:07+00:00
- Last reviewed by DSE: 2026-09-09
- Resource type: Guide
- DSE priority: Information
- Topics: Business Continuity, IT
- Reading time: 2 minutes

## What you need to know

Does an absent Azure disk-latency series mean an NVMe-backed workload has no latency?

## Potentially affected

Azure VM operators interpreting disk performance metrics for SCSI and NVMe controllers.

## DSE recommendation

Check metric availability for the actual controller before treating a missing series as a healthy result.

## Article

## Source facts

Azure’s OS Disk Latency and Data Disk Latency metrics are preview measurements available for SCSI-attached disks, not disks attached through an NVMe controller. The documented temporary-disk latency, queue-depth, read and write metrics are also unavailable for NVMe temporary storage. Disk performance metrics do not record individual create, read, update or delete operations inside a managed disk. [Microsoft Learn](https://learn.microsoft.com/en-us/azure/virtual-machines/disks-metrics).

## Applicability

Use this check while reviewing a monitoring gap after choosing or changing a VM’s storage controller. Separate an unsupported measurement from an observed value of zero, and do not describe aggregate performance monitoring as a file-operation audit.

## DSE recommendation

Check metric availability for the actual controller before treating a missing series as a healthy result. Have the monitoring owner record the controller, disk role and precise requested metric before investigating collection failure. Identify a supported measurement path for the workload’s performance question and a separately authorized audit approach if individual data access is the concern. Keep unavailable signals visibly unresolved instead of filling their chart gaps with assumed healthy values.

## Verification

On a controlled VM, confirm the actual disk/controller configuration and inspect which series are emitted. Compare supported observations with the application’s measured behavior during the same interval. Document any excluded metric so a later dashboard consumer knows why it is absent. Do not use a successful VM start or a populated neighboring chart as evidence that an unsupported latency metric has become available.

## Official references

[Microsoft Learn: Disk performance metrics](https://learn.microsoft.com/en-us/azure/virtual-machines/disks-metrics). Source reviewed September 9, 2026.

## Primary reference

- Name: Disk metrics - Azure Virtual Machines | Microsoft Learn
- Authority: Microsoft Learn
- URL: https://learn.microsoft.com/en-us/azure/virtual-machines/disks-metrics
- Source publication date: Not stated by the source

## Citation and use

Preferred citation: “Check the disk controller before interpreting missing Azure latency metrics,” DSE Security, https://update.dsesecurity.com/updates/dse-20260909-054-check-the-disk-controller-before-interpreting-missing-azure-latency-metrics/
Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/
Usage and citation policy: https://update.dsesecurity.com/usage/
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