Instance Name | The name of the VM instance. |
Device Name | The name of the disk device. |
Storage Type | The storage type: `pd-standard` or `pd-ssd`. |
Device Type | The disk type: `permanent`. |
Throttle Reason | The limit that caused the throttling: `PER_GB`, `PER_VM`, or `EMERGENCY`. The `EMERGENCY` reason is deprecated but preserved for backward compatibility; the reported value is always 0. |