If I posed the question to the readers of this blog I bet I could get a dozen or more different approaches that we could use to visualize free disk information in Operations Manager either as out-of-the-box functionality or using 3rd party solutions (for those who are interested I will be following up with a blog post summarizing options in OpsMgr, 3rd party solutions and showcase some Power BI options over the Operations Manager DW so keep an eye out here). The question here is how do we do this type of functionality with the “new kid on the block” – Microsoft OMS? My tests on this showed it to be far simpler to accomplish than I would have guessed. The blog will show the steps involved and the results available from providing visualization for free disk information using OMS.
Collecting the data on free disk space using OMS:
To gather free disk space information you will need an account in OMS (there is a free tier if you just want to try it out) and you need to have agents deployed either directly or through integrating your Operations Manager environment with OMS. One we have our OMS account and agents reporting to OMS we can use the Near real-time performance counter functionary to gather free disk space information. To add performance counters open settings and then data, and add the Windows Performance counter that you want. Please note, when you add a counter they appear with a purple line on the left side until you hit the save button at the bottom of the screen (example shown below).
The list below shows the variety of counters which I am currently gathering in my OMS subscription:
Visualizing disk space information using OMS:
Once we start collecting the data how do we visualize it in OMS? The blog post which the product team put together when they added this feature gives excellent examples and steps which are available at: http://blogs.technet.com/b/momteam/archive/2015/09/01/near-real-time-performance-data-collection-in-oms.aspx
Since that is well covered my focus will be on showing how you can see the same performance counter for multiple systems in OMS.
We start with the log search option in the top left of the OMS UI:
A great starter query which they discussed in the blog momteam blog post was to start the query with something simple such as: Type=Perf which shows all performance counters which are being collected by OMS. From there we can select the counter that we want from the left hand side and aply the change.
This changes the query up top to now be: Type=Perf (CounterName=”Free Megabytes”)
This returns data with a number of results and metrics. To see the performance data results click on Metrics.
Opening the metrics shows the graphs for each of the systems which this counter is being gathered for.
You can zoom into the results by clicking on them.
To test the responsiveness of the graph I used a trick that Steve Buchanan showed on his blog post to simulate low disk space (http://www.buchatech.com/tag/simulate-low-disk-space/). Note that the graph also shows a last value and an average value on the right hand side.
The change in free space is shown over time, and you can interact with the chart to highlight specific points on the chart.
The light-blue values on the right hand side of the graph are new data which has arrived since the graph was opened.
Summary: Adding visualizing for free disk space information in OMS was simple and once you are familiar with the log search functionality it is easy to visualize this information for multiple systems.
Update: Stanislav recommends gathering the “LogicalDisk(*)\% Free Space” counter instead as this provides a more intuitive graph to see what the level of free space is in OMS especially when you have drives of different sizes.