DB File Free Space Left

Microsoft.SQLServer.Linux.Monitor.DBFile.DBFileSpace (UnitMonitor)

The monitor reports a warning when the free space (including both already allocated space and free space on the media) drops below the Warning Threshold setting, expressed as percentage of the sum of data size plus disk free space. The monitor reports a critical alert when the free space drops below the Critical Threshold.

Knowledge Base article:

Summary

The monitor oversees the space available in the file and on the media which hosts the file. The space available on the media is only considered if autogrowth is enabled for the given file.

Causes

An unhealthy state is caused by having low available for this file. Low free space can be caused by:

Use the following link to view the performance data: DB File Free Space Performance Data

No Autogrowth

For a file that has no autogrowth, free space would be the difference between the initial size for a file and the used space.

Autogrowth Enabled

For a file with autogrowth, free space would be calculated as the available free disk space that can be used for extension of the database file with respect to the last autogrowth step size. Because the last autogrowth step size can exceed disk capacity, calculations of the free space are performed as a function of autogrowth step values. For example, if autogrowth is set to 20% on the disk, the size of which is 10 GB and the current database size is 9 GB, the free space will be displayed as 0 GB because the last gigabyte cannot be used.

Low free space for database files that have autogrowth could mean that the file is approaching the limits of the hosting logical drive. For files with autogrowth enabled with a max size, low free space could also mean that the file is approaching the max size specified for a file.

The free space calculations also take into account that the file can also fail to grow if the growth amount of the file is greater than the amount left on disk and that the file cannot grow if the difference between the max size and the current file size is less than the growth amount. In these situations, available free space left on disk is not included as part of the free space because we cannot grow any longer.

Resolutions

This issue may be resolved by either:

External

Files and Filegroups Architecture

Overridable Parameters

Name

Description

Default Value

Alert Priority

Defines Alert Priority.

Normal

Alert Severity

Defines Alert Severity.

Error

Azure Maximum File Size (MB)

The maximum size of data file stored in Azure BLOB Storage. The workflow will consider this value as a maximum storage capacity for each file.

1048576

Critical Threshold

The monitor will change its state to Critical if the value drops below this threshold. Being between this threshold and the warning threshold (inclusive) will result in the monitor being in a warning state.

10

Enabled

Enables or disables the workflow.

Yes

Generates Alerts

Defines whether the workflow generates an Alert.

No

Interval (seconds)

The recurring interval of time in seconds in which to run the workflow.

900

Synchronization Time

The synchronization time specified by using a 24-hour format. May be omitted.

 

Timeout (seconds)

Specifies the time the workflow is allowed to run before being closed and marked as failed.

300

Timeout for query execution (seconds)

The workflow will fail and register an event, if the query execution takes longer than the specified period.

60

Timeout for database connection (seconds)

The workflow will fail and register an event, if it cannot access the database during the specified period.

15

Warning Threshold

The monitor will change its state to Warning if the value drops below this threshold.

20

Element properties:

TargetMicrosoft.SQLServer.Linux.DBFile
Parent MonitorSystem.Health.PerformanceState
CategoryPerformanceHealth
EnabledTrue
Alert GenerateTrue
Alert SeverityMatchMonitorHealth
Alert PriorityNormal
Alert Auto ResolveTrue
Monitor TypeMicrosoft.SQLServer.Linux.MonitorType.DBFile.DBFileSpace
RemotableTrue
AccessibilityPublic
Alert Message
MSSQL on Linux: DB File is running out of space
DB File "{2}" for Filegroup "{3}" on database "{4}" on SQL Server instance "{1}", computer "{0}" is running out of space. See the knowledge section for more details.
Space available: {5}MB ({6}\%).
RunAsDefault

Source Code:

<UnitMonitor ID="Microsoft.SQLServer.Linux.Monitor.DBFile.DBFileSpace" Accessibility="Public" Enabled="true" Target="SqlDiscL!Microsoft.SQLServer.Linux.DBFile" ParentMonitorID="Health!System.Health.PerformanceState" Remotable="true" Priority="Normal" TypeID="Microsoft.SQLServer.Linux.MonitorType.DBFile.DBFileSpace" ConfirmDelivery="true">
<Category>PerformanceHealth</Category>
<AlertSettings AlertMessage="Microsoft.SQLServer.Linux.Monitor.DBFile.DBFileSpace.AlertMessage">
<AlertOnState>Error</AlertOnState>
<AutoResolve>true</AutoResolve>
<AlertPriority>Normal</AlertPriority>
<AlertSeverity>MatchMonitorHealth</AlertSeverity>
<AlertParameters>
<AlertParameter1>$Target/Host/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/MachineName$</AlertParameter1>
<AlertParameter2>$Target/Host/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/InstanceName$</AlertParameter2>
<AlertParameter3>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.File"]/FileName$</AlertParameter3>
<AlertParameter4>$Target/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.Filegroup"]/GroupName$</AlertParameter4>
<AlertParameter5>$Target/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.Database"]/DatabaseName$</AlertParameter5>
<AlertParameter6>$Data/Context/Property[@Name='FreeSpaceMB']$</AlertParameter6>
<AlertParameter7>$Data/Context/Property[@Name='FreeSpacePercent']$</AlertParameter7>
</AlertParameters>
</AlertSettings>
<OperationalStates>
<OperationalState ID="UnderThreshold1" MonitorTypeStateID="UnderThreshold1" HealthState="Error"/>
<OperationalState ID="OverThreshold1UnderThreshold2" MonitorTypeStateID="OverThreshold1UnderThreshold2" HealthState="Warning"/>
<OperationalState ID="OverThreshold2" MonitorTypeStateID="OverThreshold2" HealthState="Success"/>
</OperationalStates>
<Configuration>
<MachineName>$Target/Host/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/MachineName$</MachineName>
<NetbiosComputerName>$Target/Host/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/NetbiosComputerName$</NetbiosComputerName>
<InstanceName>$Target/Host/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/InstanceName$</InstanceName>
<DatabaseName>$Target/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.Database"]/DatabaseName$</DatabaseName>
<FileName>$Target/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.File"]/FileName$</FileName>
<AzureMaxFileSizeMB>1048576</AzureMaxFileSizeMB>
<ValuePropertyName>FreeSpacePercentMon</ValuePropertyName>
<Threshold1>10</Threshold1>
<Threshold2>20</Threshold2>
<ConnectionString>$Target/Host/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/ConnectionString$</ConnectionString>
<InstanceVersion>$Target/Host/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/Version$</InstanceVersion>
<InstanceEdition>$Target/Host/Host/Host/Property[Type="SqlCoreLib!Microsoft.SQLServer.Core.DBEngine"]/Edition$</InstanceEdition>
<SqlExecTimeoutSeconds>60</SqlExecTimeoutSeconds>
<SqlTimeoutSeconds>15</SqlTimeoutSeconds>
<TimeoutSeconds>300</TimeoutSeconds>
<IntervalSeconds>900</IntervalSeconds>
<SyncTime/>
</Configuration>
</UnitMonitor>