Log Analytics can be a powerful monitoring tool for your infrastructure as you can query various metrics that are important for your servers availability like disk space.
The below query can be used to get free space for your Linux VM disks.
InsightsMetrics | where Origin == "vm.azm.ms" and Namespace == "LogicalDisk" and Name == "FreeSpaceMB" | extend Disk=tostring(todynamic(Tags)["vm.azm.ms/mountId"]), Disk_Size_GB=(todynamic(Tags)["vm.azm.ms/diskSizeMB"]) / (1024) | summarize Disk_Free_Space_GB = avg(Val) / (1024) by Computer, Disk, Disk_Size_GB, _ResourceId | where Disk in ('sda1', 'sdb1', 'sdc1', 'sdd1','/') | project Computer, Disk, Disk_Size_GB, Disk_Free_Space_GB
You can also select the scope of the query in order to get results for specific resources/resource groups.
The result will bring all disks size and free space that their name is included in the list
('sda1', 'sdb1', 'sdc1', 'sdd1','/')
The same query with a small change can be applied also for windows vms in order to get the available space for your C: drive.
InsightsMetrics | where Origin == "vm.azm.ms" and Namespace == "LogicalDisk" and Name == "FreeSpaceMB" | extend Disk=tostring(todynamic(Tags)["vm.azm.ms/mountId"]), Disk_Size_GB=(todynamic(Tags)["vm.azm.ms/diskSizeMB"]) / (1024) | summarize Disk_Free_Space_GB = avg(Val) / (1024) by Computer, Disk, Disk_Size_GB, _ResourceId | where Disk in ('C:') | project Computer, Disk, Disk_Size_GB, Disk_Free_Space_GB
Finally you can pin this result inside an Azure dashboard by clicking pin and select the specific dashboard.