> For the complete documentation index, see [llms.txt](https://docs.console.zenlayer.com/welcome/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.console.zenlayer.com/welcome/elastic-compute/instance-monitoring/05-disk.md).

# How Is My Disk Behaving?

All disk panels are scoped per attached volume — pick the volume from the dropdown at the top of the section.

## Throughput — Read / Write

Bytes per second that the guest is asking the storage layer for, measured on the host side of the block device. This is the ground-truth view, independent of anything the guest reports.

## Operations (IOPS) — Read / Write

Read and write requests per second. Read together with Throughput to compute the average request size — small-block random I/O and large-block sequential I/O behave very differently and should be reasoned about separately.

## Disk Utilization

How busy the block device is, derived from cumulative service-time counters. This is the panel that distinguishes "my disk is slow" from "my disk is busy":

* **High utilization at high IOPS** — the workload is saturating its disk tier. Reduce the request rate, batch writes, or upgrade the disk tier.
* **High utilization at low IOPS** — request rate is modest but each request is slow. This points at the storage backend; contact support.

## API Reference

All disk metrics use `DescribeDiskMonitorData` with the `metricType` values below.

| Console Panel             | metricType         |
| ------------------------- | ------------------ |
| Throughput — Read         | `DISK_READ_BYTES`  |
| Throughput — Write        | `DISK_WRITE_BYTES` |
| Operations (IOPS) — Read  | `DISK_READ_OPS`    |
| Operations (IOPS) — Write | `DISK_WRITE_OPS`   |
| Disk Utilization          | `DISK_UTIL`        |