Introduction
Alert when free disk space drops below a threshold. The Disk Usage monitor lets you target any drive or the system drive specifically, and measure either by percentage or absolute gigabytes — so you can set thresholds that actually make sense for the drive size.
Disk Usage Monitor
Level checks available disk space on covered devices. When free space falls below your threshold, Level creates an alert.
Unlike the CPU and Memory monitors, Disk Usage doesn't have a breach duration — the alert fires as soon as the condition is detected. Disk space doesn't spike and recover the way CPU or RAM does, so there's no need to wait out a sustained period.
Configuring Disk Usage Monitor
Open the target monitor policy, then add or edit a Disk Usage monitor. The Edit monitor panel opens on the right.
Name and Type
Enter a name in the Name field. "Servers - Low Disk (System)" or "Workstations - Low Disk (20%)" gives you instant context in an alert list.
Set Type to Disk usage.
Severity
Set Severity to match how urgent low disk space is in this context:
Information
Warning
Critical
Emergency
💡 TIP: Two-tier disk monitoring works well: a Warning at 20% free to give you time to act, and a Critical at 10% for when it's genuinely urgent. Create two separate monitors in the same policy to cover both.
Disk Drive
Disk drive controls which drives the monitor evaluates:
Any drive — alert if any drive on the device falls below the threshold
System drive only — monitor only the drive where the OS is installed
💡 TIP: System drive only is useful for preventing false positives from secondary data drives that are expected to fill up — backup volumes, archive drives, or secondary partitions.
Measurement
Measurement controls how the threshold is expressed:
Percent free — alert when free space drops below X% of total capacity
GB free — alert when free space drops below X GB
💡 TIP: Percent free scales with drive size and works well across mixed environments. GB free is more precise when you need a hard floor — for example, ensuring a log volume never drops below 5 GB regardless of its total size.
Threshold
Threshold sets the free space value below which the alert fires. The unit displayed (% or GB) matches your Measurement selection. Adjust using the slider or up/down arrows.
Auto-Resolve
Auto-resolve alert if it is no longer applicable (enabled by default) closes the alert when free space rises back above the threshold — for example, after files are deleted or the drive is expanded.
Remediation
Attach one or more automations to run when this monitor fires — run a disk cleanup script, archive old logs, or notify your team.
Click in the Remediation field and select an automation.
To add more, click + Add another remediation.
To remove one, click the × next to it.
Once attached, open the automation from the link icon to assign the monitor's payload to an automation variable.
ℹ️ NOTE: Remediations run when the alert is created, not when it resolves.
Notifications
Send notifications on alert creation — policy recipients get an email when the alert fires
Send notifications on alert resolution — policy recipients get an email when the alert resolves
Recipients are managed at the monitor policy level, in the Recipients section.
ℹ️ NOTE: If no recipients are added to the policy, notification emails won't send regardless of these toggle states.
Saving the Monitor
Click Update monitor to save changes, or Add monitor if adding a new one.
FAQ
Who can create and edit monitors? Technicians with access to the relevant monitor policy. Permission settings are managed in Workspace → Permissions.
Should I use "Percent free" or "GB free"? Percent free works well for most environments since it scales with drive size. GB free is useful when you need a hard minimum — for example, ensuring a SQL server always has at least 10 GB available regardless of total disk capacity.
Why is my disk alert not firing even though I know a drive is nearly full? Confirm the device is covered by the policy's target tags, and check whether Disk drive is set to System drive only — a nearly full secondary drive won't trigger that configuration.
Can I monitor specific drive letters? The built-in Disk Usage monitor supports Any drive or System drive only. To monitor a specific drive letter or path, use a Script Monitor with a custom script.
What happens to open disk alerts if I delete the monitor? Existing alerts remain in place. Deleting a monitor doesn't close alerts it already created — resolve those manually.