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Alex Kobin's avatar
Alex Kobin
Copper Contributor
Aug 16, 2018
Solved

Query How to find disk free space in % in LINUX VM's

Hi everyone
I'm looking for a query that will show me a free disk space in % in Linux VM's.
For now i got a query that suppose to show me what i need but the results is wrong for LINUX VM's.
So i wonder maybe someone got this done before and got a query for this, or what is wrong in my query?
 
Perf
| where TimeGenerated > ago(5m)
| where ((ObjectName == "LogicalDisk" and CounterName == "% Free Space") or (ObjectName == "Logical Disk" and CounterName == "% Used Space"))
| summarize (TimeGenerated, Free_Space_Percent)=arg_max(TimeGenerated, CounterValue) by Computer, InstanceName
azure monitor
Query Language
  • Noa Kuperberg's avatar
    Noa Kuperberg
    Aug 20, 2018

    Hi,

    Indeed,"% Free Space" is a performance log sent from Windows. Linux is reporting "% Used space" instead, and unfortunately the object name is slightly different (with space), try this:

    Perf 
| where ObjectName == "Logical Disk" and CounterName == "% Used Space" 
| summarize arg_max(TimeGenerated, *) by Computer

    The 'arg_max' line is optional. I used it to return only the latest report per computer. Note this is the percent of used space, if you need free space you add this line:

    | extend free_space=100-CounterValue

    and the calculated value would appear as the right-most column on the results table.

     

    HTH,

    Noa

3 Replies

  • Noa Kuperberg's avatar
    Noa Kuperberg
    Icon for Microsoft rankMicrosoft
    Aug 20, 2018

    Hi,

    Indeed,"% Free Space" is a performance log sent from Windows. Linux is reporting "% Used space" instead, and unfortunately the object name is slightly different (with space), try this:

    Perf 
| where ObjectName == "Logical Disk" and CounterName == "% Used Space" 
| summarize arg_max(TimeGenerated, *) by Computer

    The 'arg_max' line is optional. I used it to return only the latest report per computer. Note this is the percent of used space, if you need free space you add this line:

    | extend free_space=100-CounterValue

    and the calculated value would appear as the right-most column on the results table.

     

    HTH,

    Noa

    • GouravIN's avatar
      GouravIN
      Brass Contributor
      Sep 01, 2018

      Hi Noa,

       

      I have tried below query  but i am getting data C drive

       

      Perf
      | where ObjectName == "LogicalDisk" and CounterName == "% Free Space" and InstanceName == "C:" 
      | summarize arg_max(TimeGenerated, *) by Computer

       

       

      But when i am trying to get data for all drives i am only getting for F:, Z:, H:, E: drive. Its strange that i am not getting for data for C: drive and other some drives. do not know why?

       

      Perf
      | where ObjectName == "LogicalDisk" and CounterName == "% Free Space" and InstanceName contains ":"
      | summarize arg_max(TimeGenerated, *) by Computer
      • Patrick Naughton's avatar
        Patrick Naughton
        Brass Contributor
        Sep 04, 2018
        Perf
        | where ObjectName == "LogicalDisk" and CounterName == "% Free Space"
        | summarize arg_max(TimeGenerated, CounterValue) by Computer, InstanceName

        arg_max was returning only a instance (the one with the most recent value) per computer in the form you used it in your question.

         

        the query above will give you the most recent %Free for every logical disk.

         

         

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