OpsMgr: Logical Disk free space alerts don’t show percent and MB free values in the alert description


NOTE:  This article has been updated – please see the latest version at:




I recently wrote about the new Base OS Monitoring Packs that shipped, adding many new features and fixes for monitoring the OS.  You can read more about that new release HERE.   While this MP update contained many fixes and new features which are VERY beneficial in making alerts more actionable by controlling “false positives”, some of these modifications left a bit of a negative side effect.

One of the areas this new MP focused on, was changing a lot of the “average threshold” monitors to “consecutive sample” monitors.  This helps control the noise when there are short term fluctuations in a performance value, or when some counters can spike tremendously for a very short time, skewing the average.  So for the most part – changing these over to consecutive samples is a good thing.  That said, one of the changes made was to the Logical Disk free space monitors, both for Windows Server 2003 and 2008 disks.

The script used to monitor logical disk free space in previous versions of the Monitoring Pack would output two additional propertybags for free space in MB and Percent.  This was very useful, because these values could easily be added to the alert description, alert context, and health explorer.  This was very beneficial, because the consumer of the alert in a notification knew precisely how much space was left for each and every alert generated.  Here are some examples of how it looked previously:






Now – when the new MP shipped – this script was changed to support the new consecutive samples monitortype, and was completely re-written.  When it was rewritten, the script no longer returned these propertybags, so they were removed from the alert description, alert context, and health explorer.  The current MP (6.0.6958.0) looks like this:


The monitor still works perfectly as designed, and you are alerted when thresholds that you set are breached.  The only negative side effect is the loss of information in the alert description.

Several customers have indicated that they preferred to have these values back in the alert description.  The only real way to handle this scenario, until the signed and sealed MP gets updated at some point in the future, is to disable the built in monitor, and enable a new monitor with an alert description that you like.

I have written two addendum MP’s attached at the bottom of this article, which do exactly that – I created two new monitors (essentially the same monitors from the previous older version of the Base OS MP’s) and included two overrides which disable the existing monitors from the sealed MP’s.  These two new monitors are essentially exact copies of the monitors before they got updated.  They run once per hour and have all the default settings from the previous monitors.

With the addendum MP imported – health explorer looks like the following:


Note the new name for the addendum monitor, and the fact that the existing “Logical Disk Free Space” monitor is unloaded as it is disabled via override.


These addendum MP’s for Windows Server 2003 and Windows Server 2008 each simply include a script datasource, monitortype, and monitor to use instead of the items in the current sealed Base OS MP’s.  These addendum MP’s are unsealed, so you have two options:

  1. Leave them unsealed, and use them as-is.  This allows you to be able to tweak the monitor names, alert descriptions, and any other settings further.
  2. Seal the MP’s with your own key (recommended) after making any adjustments that you desire.  This will be necessary in order to create overrides for existing groups in other MP’s should you desire to use those.


One caveat to understand – is that any overrides you have created on the existing Base OS free space monitors will have to be re-created here on these new ones.  There is no easy workaround for that.

Let me know if you have any issues using these addendum MP’s (which are provided as a sample only) and I will try to address them.


Credits – to Larry Mosley at Microsoft for doing most of the initial heavy lifting writing the workaround MP.

Another approach:  Daniele Grandini has authored a different solution to this issue.  What he has done, is to add diagnostics to the existing sealed Logical Disk Free space monitors, which will add the actual disk free space in MB and % to Health explorer, so console users can have this information in real time as they use alert/health explorer to troubleshoot a free space issue.  His solution will not be able to add these values to the alert description to be sent in an email notification/pager/ticket, but for those companies that use the console and health explorer, it is a more graceful solution in that you don’t have to re-engineer all your existing overrides, and you still get the benefit of having consecutive samples.  It is worth a look:  http://nocentdocent.wordpress.com/2011/11/19/opsmgr-logical-disk-free-space-alerts-dont-show-percent-and-mb-free-values-in-the-alert-description/comment-page-1/#comment-1018


Comments (44)

  1. Kevin Holman says:

    @Brandon –

    It appears you didnt read this part of the article.  🙂

    These addendum MP’s are unsealed, so you have two options:

    1.Leave them unsealed, and use them as-is.  This allows you to be able to tweak the monitor names, alert descriptions, and any other settings further.

    2.Seal the MP’s with your own key (recommended) after making any adjustments that you desire.  This will be necessary in order to create overrides for existing groups in other MP’s should you desire to use those.

  2. Murad Akram says:

    Hi Kevin,

    Do you know if this is changed/updated in SCOM 2012 CU1?

    Thanks – Murad

  3. Kevin Holman says:

    @George –
    Unfortunately – the way SCOM is designed, an alert is generated on the state change. However once an alert is generated – we will not generate additional alerts for further state changes to another unhealthy condition. Therefore, all we do is update the existing alert’s severity. However, this update of an alert does NOT generate a new notification. Therefore, if you have different actions needed, such as email when warning, but autoticket when critical, this breaks the process if you are alerting on both state conditions. For this reason, I do not recommend 3 state monitors, or at least I don’t recommend generating alerts on the warning state, for customers who experience this challenge.

  4. Thanks Kevin for this wonderful work

  5. Kevin Holman says:

    @George – I have no idea what you are asking. Do you mean create additional alerts each time the disk fills MORE, after the original critical alert is generated? If that is the case, no – this is not possible – because the alert is generated one time based on a state change from healthy to unhealthy, this is just how monitors work. If you wanted something like what you describe – you could use Orchestrator to monitor for all disks that are full, then create and/or modify alerts with updated information via the SDK.

  6. Kevin Holman says:

    @Brandon – alerts on the warning state are BAD BAD BAD for any three state monitor.  

    Here is why – when we alert on the warning state, you get a nice proactive notification.  However, when the monitor then goes from warning to critical status – we do NOT issue a NEW alert – we simply modify the existing alert from warning to critical.  This does not trigger a new notification, especially bad for customers who leverage incident management systems, as the warning alert will already be processed by their connector – then the disk will fill and potentially crash the server and they will never raise an incident.  I never recommend notifications on wanring states.  For customers who want this – I recommend two monitors, one with a warning threshold, and one with a critical threshold – so they can have independent control over this.  If we would change the product so that a monitor can issue a NEW alert on change from warning to critical – this would resolve this issue.

  7. Anonymous says:

    Oops, found the problem, member in the group didn't seem to be right, re-added the member which search from windows server 2008 class, then recreated the override, it is working now.


  8. Hi Kevin,

    sounds great. I've just implemented the new MP at three customers and everyone wants to have the free space information back in the alert. You mention only Server 2003 and Server 2008 – will it work with 2008 R2 too. I guess – it's just because all monitors are only listed for "2003" or "2008" – right?

    Thanks – Peter Forster, Microsoft MVP 2002-2011

  9. Kevin Holman says:

    @MuradAkram –

    We dont change the management packs for a different SCOM version – the BaseOS MP is the same between versions.  All MP's for the time being will be written to work with either version of SCOM.  So – the answer is no – this has not changed for SCOM 2012 CU1.

  10. Kevin Holman says:

    @ Hare Krishna Agrawal

    That is a GREAT request.  I dont have such a thing built, but It would not be terribly difficult to do, using the existing addendum MP I published.

    We did  add similar functionality to this, in the lastest base OS mp, because we added an aggreate rollup monitor which can be used for critical rollup and critical alerting, then warning alerts from the child unit monitors.

  11. Kevin Holman says:

    @John –

    They will work fine in SCOM 2012.  No changes of any kind are necessary.

    I was holding off to write an addendum for Server 2012 logical disks – I'm hoping this gets "fixed" in a future release of the Base OS MP soon.

  12. Kevin Holman says:

    @Peter –

    Not exactly.

    The ORIGINAL script WAS set to 3600 seconds (once per hour).  Only in the new MP's with the monitor that does not return the output we like, was it changed to 900 seconds (15 minutes).  This is because it ran every 15 minutes, but required 4 consecutive samples to create a state change, therefore BOTH monitors (old and new) detect the disk space condition after 1 hour.

  13. Anonymous says:

    Hi Kevin,

    The above MP has reference to SCOM 2007 R2 libraries. One of my customer is still running SCOM 2007 SP1.

    Is it OK to change the reference of SCOM 2007 R2 libraries to SCOM 2007 SP1 libraries?

    WIll it work?



  14. Anonymous says:

    Can anyone tell me if the new re-write can handle terabyte sizes and give back proper results for % and Mb free?  the old one could not handle TB size drives.  Also, does the re-write still use perf counters or does it now enumerate via WMI?  I do not have a dev SCOM env to play with it.

  15. Kevin Holman says:

    @ pramodky99 –

    Yeah – you can change them back to SP1 versions in the manifest of the XML.  There is no dependence on R2 that I am aware of.  It just defaults to those since I am running R2.

  16. Anonymous says:

    Hi Kevin,

    I am having problem with low disk free space monitor override on my SCOM 2012 system, I created override for Logical Disk Free Space for monitoring windows 2008 R2, as POC, I created a group with that windows 2008 R2 server as the only member in it, also I am only using error MByte threshold and error % threshold. When this override target to Windows server 2008 Logical Disk it works OK, but if the target is the group I created, it doesn't work.

    The base OS MP verion is 6.0.6972.0

    Do you see the reason of this?

  17. Pavel Dzemyantsau says:

    ah, again you are too fast, Kevin.

    I had the same blog post in drafts with almost the same addendum MP.

    BTW not only this monitor was changed to Consecutive.

  18. Bob Cornelissen says:

    Same here, most customers want to have the info in the alert.

    @ Peter: Yes its just one monitor for 2003 and one for 2008.

    @ Pavel: I was also planning on creating it myself, Larry and kevin saved me that work 🙂

  19. I've made a task to show free space on all drives of the server 🙂

  20. Enrique Moreno (emorenov@bankia.com) says:

    Hi Kevin,

    I´m sure you have noticed that there are some monitors more in the same state: Average Logical Disk Seconds Per Transfer and Memory Pages Per Second. Do you know if Microsoft will correct this situation or have we to do the same that you did with Logical Disk Space Free? Thanks in advanced.

  21. Peter says:

    Thanks Kevin, works perfect.

    Only one remark: the schedule in your MP is set to 3600 while the original one is at 900 seconds.

    Some people might wanna change that to have smaller intervals.

  22. BrandonBaang says:


    It seems like your addendum MP doesn't support override on custom groups.  Could you please confirm?  I have a group called "Tier1 Servers" which require more aggresive thresholds.  I only see the "default" groups when I tried to create an override for my Tier1 group.  Thank you.

  23. santosh Dharamsale says:

    After importing this MP i am unable to see the difference why? do i need to do some changes?  

  24. BradonBaang says:

    Hi Kevin,

    Brandon again ^^  Everything looks good after sealing the management pack.  One more thing, however.  I have noticed that your MP doesn't contain option option to generate alerts for the warning state, whereas the original base MP does have this option.  This option is particularily useful when monitoring disk space on our Tier1 servers.  Thanks!

  25. Mukesh Kharade says:

    SCOM issue? Yeah Kevin blogs are only solution..Wonderful work Kevin.

  26. Pramod says:

    Hi Kevin,

    Thanks for comfirmation. Since it was urgent, So I did the changes in XML, tested it and applied. Its working fine.


  27. Hi Kevin,

    I need to create two monitors for Logical Disk which alerts when monitor is in Warning and Critical state respectively. This will address issues where SCOM doesn't sends a notification if the state changes from Warning -> Critical or Critical -> Warning. This is essential as we have integration with Incident Management.

    Also in my monitors I wanted to add the %free space and free MB available. I tried creating Unit monitors using Windows Performance Counters but when I tested your MP, it was using Microsoft.Windows.Server.2003.Addendum.LogicalDisk.FreeSpace.ModuleType.

    Do you have any MP which caters to both these requirements.

    This is like asking too much, but wanted to check if you already have.



  28. Kiwifulla2 says:

    Hi Kevin

    Is this still valid for the latest OS MP (6.0.7026.0) ?  I have been recommended to import your MP to address an issue where I want to increase the script running duration from 300 seconds on the % Logical Disk Free Space 2008 Rule for a very large volume on a file server (as this times out), however there is no UI to override this value and another social.technet member has mentioned your MP could be the answer?



  29. Kiwifulla2 says:

    Following up on my original question, firstly I was wrong about this being a rule, it is actually timing out on the monitor "Logical Disk Free Space" which is what is in your Addendum MP…but the issue remains, there is no UI to change the duration/timeout as far as I can see?


  30. Kiwifulla2 says:

    Oops, there IS an override UI called TimeoutSeconds (sorry) so that should do it!  

    I see that in the newer MP 6.0.7026.0 though, the System Drive Warning MB Threshold is 500 (not 200 as per the Addendum MP) so I will override that too as I presume this is higher in the new MP from more recent lessons learned/feedback/testing.

    Kevin, can you please confirm that this Addendum MP is safe to use with the new OS MP version 6.0.7026.0?

    Thanks and again, sorry for the incorrect info initially posted.


  31. David says:

    Sometimes the logic behind the configuration decisions made by the teams that develop these MP's just amazes me!

    I mean, why would you want pertinent information in an alert right? Who needs their customers to ask "why doesn't the alert email tell me what the threshold is and the current level?".

    And my main question, why should SCOM admins spend hours of time engineering their way around fundamental logic gaps in the product?


  32. David says:

    And has this logic gap been plugged in a subsequent release of the MP?

  33. John says:

    Hi Kevin,

    Will these addendum packs work with SCOM 2012? Would I just have to change the pre-requisite MP versions in the .XML file to the SCOM 2012 MP versions?

  34. Keithk2 says:


    I just submitted a post before, but I was wrong about the 2012 mp not having the old model (one monitor/2 conditions) of disk modeling.  It is there!  You can disregard my previous post.  Based on your last post I will continue to look to (and hope) that the missing details for 2012 logical disk monitoring get added.



  35. Olli says:

    Do you have anyidea is this problem going to be fixed?

    We are planned migrate to SCOM 2012 from another monitoring software and this is very important thing to get fixed.

    We also have already lot of servers with 2012 OS.

  36. Thanks for the very useful article.

    We have many 2012 servers in our environment, so that we need to target the monitor to Windows 2012 Logical Disk class.

    It would be very helpful for us, If you tell me, how to create the custom monitor with % free space and MB free space details.

    Thanks in advance.

  37. Mathew Perkins says:

    Hello Kevin, When i try to seal these management packs to use them efficiently, It tells me that it cannot seal them as it is unable to find a seperate default management pack. Are you aware of this error within SCOM 2012?

  38. Simon says:

    Any addendum for Windows 2012 Logical disk available?

  39. Anonymous says:

    Microsoft’s very own Kevin Holman just posted a great article over on his blog talking about an issue

  40. Anonymous says:

    Microsoft’s very own Kevin Holman just posted a great article over on his blog talking about an issue

  41. Anonymous says:

    Pingback from Logical Disk free space alerts don???t show percent and MB free values in the alert description in OpsMgr 2007 – System Center Mindenkinek – TechNetKlub

  42. Anonymous says:

    I previously wrote about some updated Base OS Monitoring Packs that shipped, adding many new features

  43. George says:

    Hi Kevin, Is there any possible way to modify the "disk free space monitor" (script) to alert on percentage change below the threshold? Customers would like to see the "change" in the Alert description as well as get notified when that change occur within
    the critical healthstate. i.e. alert on base threshold 5%, then 4%,3% etc. Thanks for your help.

  44. George says:

    Hi Kevin, Thanks for the explanation. I have another question regarding subscriptions Alert email notification. Is there a way to send email notification on both health states ( Warning and/or Critical) for the same resolution state: 0 (New)? Example: send notification when free disk space is in Warning health state and then when disk free space falls in Critical health state send another email notification. Currently seems that SCOM 2007 R2 subscriptions send only 1 email notification regardless of health state. To be clear, if disk free space falls in Warning state then subscription will not send another email notification when disk free space falls in Critical state. Customers would prefer to be notified for each health state (Warning and Critical). Thanks for your help.

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