Logical Disk \% Free Space

Microsoft.Linux.SLES.9.LogicalDisk.PercentFreeSpace.Monitor (UnitMonitor)

SUSE Linux Enterprise Server 9 Logical Disk \% Free Space Monitor

Knowledge Base article:


The percentage of free space on the logical disk (file system) is low. System performance may be adversely affected, and the ability to add or modify existing files on the file system may be at risk until additional free space is made available.

The file system space reserved for the root user is not included in the calculated free space. File system space usage is calculated with current free and total values, which may not accurately represent true usage for file systems that dynamically allocate space, such as ZFS.

The monitor threshold is analyzed against an average of values returned in polls to the agent, where the Number of Samples parameter controls the number of samples included in the calculation of the average.

This monitor has been superseded by the corresponding Logical Disk Free Space monitor, which implements configurable Warning and Error free space thresholds by both percentage and megabyte. If the corresponding Logical Disk Free Space monitor is enabled, disable this monitor with an override.


Default Configuration


Default Value



Interval (seconds)


Number of Samples


Overrides can be used to change the parameter values defined above for all instances or for specific instances or groups.


When existing files grow in size and the new files are added, the free space is taken up on a file system. When the amount of free space on the file system falls below the threshold, the state for the Logical Disk will change.


To increase the amount of available disk space, do one or more of the following:

To view recent file system capacity history you can use the following view:

Disk Capacity

Element properties:

Parent MonitorSystem.Health.AvailabilityState
Alert GenerateTrue
Alert SeverityError
Alert PriorityNormal
Alert Auto ResolveTrue
Monitor TypeMicrosoft.Unix.WSMan.Performance.Filtered.Average.Threshold.MonitorType
Alert Message
\% Free Space is too low
The threshold for the Logical Disk\\% Free Space performance counter has been exceeded. The value that exceeded the threshold is: {0}\% Free Space.

Source Code:

<UnitMonitor ID="Microsoft.Linux.SLES.9.LogicalDisk.PercentFreeSpace.Monitor" Accessibility="Public" Target="Microsoft.Linux.SLES.9.LogicalDisk" TypeID="Unix!Microsoft.Unix.WSMan.Performance.Filtered.Average.Threshold.MonitorType" Enabled="true" ParentMonitorID="SystemHealth!System.Health.AvailabilityState">
<AlertSettings AlertMessage="Microsoft.Linux.SLES.9.LogicalDisk.PercentFreeSpace.AlertMessage">
<OperationalState HealthState="Error" MonitorTypeStateID="UnderThreshold" ID="UnderThreshold"/>
<OperationalState HealthState="Success" MonitorTypeStateID="OverThreshold" ID="OverThreshold"/>
<ObjectName>Logical Disk</ObjectName>
<CounterName>% Free Space</CounterName>