Added collector docs, entry to readme

Signed-off-by: pgibbs1 <pgibbs1@liberty.edu>

docs/README.md

@@ -6,6 +6,7 @@ This directory contains documentation of the collectors in the windows_exporter,
 - [`adfs`](collector.adfs.md)
 - [`cpu`](collector.cpu.md)
 - [`cs`](collector.cs.md)
+- [`diskdrive`](collector.diskdrive.md)]
 - [`dfsr`](collector.dfsr.md)
 - [`dhcp`](collector.dhcp.md)
 - [`dns`](collector.dns.md)

docs/collector.diskdrive.md

@@ -0,0 +1,41 @@
+# diskdrive collector
+
+The diskdrive collector exposes metrics about logical disks (in contrast to physical disks)
+
+|                     |                                                                                                                                                              |
+| ------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------ |
+| Metric name prefix  | `diskdrive`                                                                                                                                                  |
+| Classes             | [`Win32_PerfRawData_DNS_DNS`]                                                 (https://learn.microsoft.com/en-us/windows/win32/cimwin32prov/win32-diskdrive) |
+| Enabled by default? | No                                                                                                                                                           |
+
+## Flags
+
+None
+
+## Metrics
+
+| Name                      | Description                                                                                                                                                      | Type    | Labels |
+| ------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------- | ------ |
+| `disk_drive_info`         | General identifiable information about the disk drive                                                                                                            | gauge   | None   |
+| `disk_drive_availability` | Power-related                                                                                                                                                    | counter | None   |
+| `disk_drive_partitions`   | Number of paritions on the drive                                                                                                                                 | gauge   | None   |
+| `disk_drive_size`         | Size of the disk drive. It is calculated by multiplying the total number of cylinders, tracks in each cylinder, sectors in each track, and bytes in each sector. | gauge   | None   |
+| `disk_drive_status`       | Operational status of the drive                                                                                                                                  | counter | None   |
+
+## Alerting examples
+**prometheus.rules**
+```yaml
+groups:
+- name: Windows Disk Alerts
+  rules:
+
+  # Sends an alert when disk space usage is above 95%
+  - alert: Drive_Status
+    expr: windows_disk_drive_status{status="OK"} != 1
+    for: 10m
+    labels:
+      severity: high
+    annotations:
+      summary: "Instance: {{ $labels.instance }} has drive status: {{ $labels.status }} on disk {{ $labels.name }}"
+      description: "Drive Status Unhealthy"
+```