[fusion_text]Running out of free disk space can cause serious production issues, but it is a problem that can be easily avoided. Using Netreo, users can get low disk alerts for Azure VMs (both Windows and Linux), as well as for Azure VM Scale Sets.
After completing the Setup Wizard and adding the necessary VMs to be monitored, Netreo will automatically, as a part of its default setup raise alerts if any of the drives have less than 1GB of free space left.
If it is necessary to raise alerts using different criteria or if you’re not yet monitoring VMs with Netreo, follow the following steps
1. Run Netreo Setup Wizard to connect to your Azure environment
If you aren’t using Netreo yet, request a demo to have a sales representative, show you the view of an Azure subscription with Azure VMs. Learn more about the setup process here.
2. How to modify the threshold of the alert condition to be a different amount
When configuring monitoring for a new Azure resource, users may use provided default templates that include popular metrics, alerts, and auto-scaling rules. The default template for monitoring Azure Windows VMs contains a “Low Disk Space” alert which is raised whenever the free space on any individual disk is below 1GB.
To modify the threshold value:
- In the VM Configuration Dialog, go to the “Alerts” tab and open the “Low Disk Space” alert editor.
- Replace the threshold value (1024) in the alert condition with the desired value, e.g. 512. Note that the value is expressed in MB.
- Note: it is important to keep the condition verifying DiskFreeSpaceTotal in place, as it guarantees that this alert will function properly only when metric data is present.
- Contains sub-expression ensures that Netreo only tracks volumes with assigned drive letters and ignores any system partitions.
3. How to raise alerts on a single specific drive (or drives)
In certain situations, it may be also desirable to also track free disk space of particular disks. The definition of an alert tracking low disk space of an individual disk is very similar to the “Low Disk Space” alert included in the default template.
To define a custom alert for disk C:
- Go to the Alerts tab and click the “Add New Alert” button.
- Ensure that the Enabled checkbox is ticked.
- In the “Expression” textbox, type the following condition: Any(DiskFreeSpace, “Value < 2048 && Instance == C:”)””)