# logical_disk collector

The logical_disk collector exposes metrics about logical disks (in contrast to physical disks)

|                     |                  |
|---------------------|------------------|
| Metric name prefix  | `logical_disk`   |
| Data source         | Performance Data |
| Counters            | `LogicalDisk`    |
| Enabled by default? | Yes              |

## Flags

### `--collector.logical_disk.volume-include`

If given, a disk needs to match the include regexp in order for the corresponding disk metrics to be reported

### `--collector.logical_disk.volume-exclude`

If given, a disk needs to *not* match the exclude regexp in order for the corresponding disk metrics to be reported

### `--collector.logical_disk.enabled`

Comma-separated list of collectors to use. Available collectors: metrics, bitlocker_status. Defaults to metrics, if not specified.

## Metrics

| Name                                             | Description                                                                                        | Type    | Labels                                                            |
|--------------------------------------------------|----------------------------------------------------------------------------------------------------|---------|-------------------------------------------------------------------|
| `windows_logical_disk_info`                      | A metric with a constant '1' value labeled with logical disk information                           | gauge   | `disk`,`filesystem`,`serial_number`,`volume`,`volume_name`,`type` |
| `windows_logical_disk_requests_queued`           | Number of requests outstanding on the disk at the time the performance data is collected           | gauge   | `volume`                                                          |
| `windows_logical_disk_avg_read_requests_queued`  | Average number of read requests that were queued for the selected disk during the sample interval  | gauge   | `volume`                                                          |
| `windows_logical_disk_avg_write_requests_queued` | Average number of write requests that were queued for the selected disk during the sample interval | gauge   | `volume`                                                          |
| `windows_logical_disk_read_bytes_total`          | Rate at which bytes are transferred from the disk during read operations                           | counter | `volume`                                                          |
| `windows_logical_disk_reads_total`               | Rate of read operations on the disk                                                                | counter | `volume`                                                          |
| `windows_logical_disk_write_bytes_total`         | Rate at which bytes are transferred to the disk during write operations                            | counter | `volume`                                                          |
| `windows_logical_disk_writes_total`              | Rate of write operations on the disk                                                               | counter | `volume`                                                          |
| `windows_logical_disk_read_seconds_total`        | Seconds the disk was busy servicing read requests                                                  | counter | `volume`                                                          |
| `windows_logical_disk_write_seconds_total`       | Seconds the disk was busy servicing write requests                                                 | counter | `volume`                                                          |
| `windows_logical_disk_free_bytes`                | Unused space of the disk in bytes (not real time, updates every 10-15 min)                         | gauge   | `volume`                                                          |
| `windows_logical_disk_size_bytes`                | Total size of the disk in bytes (not real time, updates every 10-15 min)                           | gauge   | `volume`                                                          |
| `windows_logical_disk_idle_seconds_total`        | Seconds the disk was idle (not servicing read/write requests)                                      | counter | `volume`                                                          |
| `windows_logical_disk_split_ios_total`           | Number of I/Os to the disk split into multiple I/Os                                                | counter | `volume`                                                          |
| `windows_logical_disk_readonly`                  | Whether the logical disk is read-only                                                              | gauge   | `volume`                                                          |
| `windows_logical_disk_bitlocker_status`          | BitLocker status for the logical disk                                                              | gauge   | `volume`,`status`                                                 |

### Warning about size metrics
The `free_bytes` and `size_bytes` metrics are not updated in real time and might have a delay of 10-15min.
This is the same behavior as the windows performance counters.

### Example metric
Query the rate of write operations to a disk
```
rate(windows_logical_disk_read_bytes_total{instance="localhost", volume=~"C:"}[2m])
```

Logical Volume information
```
windows_logical_disk_info{disk_id="0",filesystem="",serial_number="",type="",volume="HarddiskVolume2",volume_name=""} 1
windows_logical_disk_info{disk_id="0",filesystem="",serial_number="",type="",volume="HarddiskVolume3",volume_name=""} 1
windows_logical_disk_info{disk_id="0",filesystem="NTFS",serial_number="668EEC37",type="fixed",volume="C:",volume_name="Windows"} 1
windows_logical_disk_info{disk_id="1",filesystem="NTFS",serial_number="50AE953B",type="fixed",volume="D:",volume_name="Temporary Storage"} 1
windows_logical_disk_info{disk_id="1",filesystem="ReFS",serial_number="C69B59AD",type="fixed",volume="G:",volume_name="Volume"} 1
```

## Useful queries
Calculate rate of total IOPS for disk
```
rate(windows_logical_disk_reads_total{instance="localhost", volume="C:"}[2m]) + rate(windows_logical_disk_writes_total{instance="localhost", volume="C:"}[2m])
```

Show volume usage (%)
```
100.0 - 100 * (windows_logical_disk_free_bytes{instance="localhost", volume="C:"} / windows_logical_disk_size_bytes{instance="localhost", volume="C:"})
```

Disk Activity
```promql
  (
      rate(windows_logical_disk_read_seconds_total[2m])
    +
      rate(windows_logical_disk_write_seconds_total[2m])
  )
/
  (
      rate(windows_logical_disk_read_seconds_total[2m])
    +
      rate(windows_logical_disk_write_seconds_total[2m])
    +
      rate(windows_logical_disk_idle_seconds_total[2m])
  )
```

## Alerting examples
**prometheus.rules**
```yaml
groups:
- name: Windows Disk Alerts
  rules:

  # Sends an alert when disk space usage is above 95%
  - alert: DiskSpaceUsage
    expr: 100.0 - 100 * (windows_logical_disk_free_bytes / windows_logical_disk_size_bytes) > 95
    for: 10m
    labels:
      severity: high
    annotations:
      summary: "Disk Space Usage (instance {{ $labels.instance }})"
      description: "Disk Space on Drive is used more than 95%\n  VALUE = {{ $value }}\n  LABELS: {{ $labels }}"

  # Alerts on disks with over 85% space usage predicted to fill within the next four days
  - alert: DiskFilling
    expr: 100 * (windows_logical_disk_free_bytes / windows_logical_disk_size_bytes) < 15 and predict_linear(windows_logical_disk_free_bytes[6h], 4 * 24 * 3600) < 0
    for: 10m
    labels:
      severity: warning
    annotations:
      summary: "Disk full in four days (instance {{ $labels.instance }})"
      description: "{{ $labels.volume }} is expected to fill up within four days. Currently {{ $value | humanize }}% is available.\n VALUE = {{ $value }}\n LABELS: {{ $labels }}"
```
