The monitor reports a warning when the available 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 available space drops below the Critical Threshold.
Knowledge Base article:
Summary
The monitor oversees the space available in the log file and on the media which hosts the log file. The space available on the media is considered as a part of the available space if auto grow is enabled for at least one of the files.
Causes
An unhealthy state is caused by having low available space across all log files. Low available space can be caused by:
Inadequate file configuration settings (size, max size, auto grow, etc.)
Inadequate space left on media
Lack of periodic regular backups
Log not truncating
Use the following links to view the performance data: DB File Log Free Space Performance Data
This monitor aggregates the space available for each log file within a database depending on each file’s configuration:
No Auto Grow
For a file that has no auto grow, available space would be the difference between the initial size for a file and the used space.
Auto Grow Enabled
In addition to the difference between the file size and the used space, the available space for files with auto grow enabled would be the minimum of either the difference between the max size and the file size and the free space left on disk.
Low available space for database files that have auto grow could mean that the file is approaching the limits of the hosting logical drive. For files with auto grow enabled with a max size, low available space could also mean that the file is approaching the max size specified for a file.
The available 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 available space because we cannot grow any longer.
Resolutions
This issue may be resolved by either:
Increasing the allocated size for log files if auto grow is disabled
Increasing the max size value for a log file if auto grow is enabled
Enabling auto grow for at least one file
Moving log files to another drive with more free space if growth space is limited
Performing regular backups of log files for FULL and BULK-LOGGED recovery modes
Investigate why log is not getting truncated:
Long open running active transactions
Long running backup operations
Replicated transaction open for a long time (Transactional Replication)
Mirror lagging behind principal server (Database Mirroring)
Modifying the thresholds for this monitor to suit the workload
Alternatively if log file available space is not a concern for the database:
Disable this monitor for this specific database or all databases
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
Enabled
Yes
Generates Alerts
Yes
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.
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
Warning Threshold
The monitor will change its state to Warning if the value drops below this threshold.
20
Timeout (seconds)
Specifies the time the workflow is allowed to run before being closed and marked as failed.
Home
ENU