Monitor VMware using OMS Log Analytics

Summary: Use OMS Log Analytics to monitor VMware

NOTE: This blog post refers to a custom built (do it yourself) method to bring in VMWare monitoring information into Log Analytics. This was an interim method to help customers to gain insights into their VMWare environment until we released our dedicated VMWare monitoring solution. This VMWare solution is described in the VMWare monitoring with OMS - Public Preview blog post and the More about VMWare Monitoring Solution blog post. You should refer to those blog posts and not to this blog post for the VMWare Monitoring Solution. The techniques described in this blog post are not compatible with the VMWare Monitoring Solution.

Hello, this is Keiko Harada, and I am a Program Manager on the Microsoft Operations Management Suite team. One of the top requests from you (our customers!) is monitoring of VMware.

So here it is:

Screenshot of results that monitor VMware in Microsoft Operations Management Suite.

In this blog post, I will show you how to set up OMS to collect and to process the VMware (ESXi Host and vCenter) logs. As an added bonus, I will even show you some example OMS query strings that you can immediately put into production to provide deep insights into your existing VMware environment.

Set up OMS to collect data from VMware

  1. As a first step, you set up the VMware environment so that the logs can be consolidated into a single syslog and be sent to a vCenter Server. You can have multiple ESXi Hosts forward syslog to a single vCenter server. I use the native vCenter and ESXi Host syslog capabilities. For this blog post, I’ve used the latest vCenter server and ESXi Host version 6.0. This can be done with 5.X version as well.

For detailed steps that set up syslog forwarding on ESXi Host, see Configuring syslog on ESXi 5.x and 6.0 (2003322).

Illustration that shows how syslog forwarding sends information to OMS.

Next, install the OMS Windows Agent on vCenter Server. For setup instructions, see Connect Windows computers to Log Analytics.

  1. After you install the OMS Windows Agent, you set up the OMS custom logs so that syslog will be collected. For details about how to set up custom logs, see Custom logs in Log Analytics.

Set up the following syslog file as your custom log on the vCenter Server.   “C:\ProgramData\VMware\vCenterServer\data\vmsyslogcollector\yourESXihostname\syslog.txt”.

For this example, I created an OMS custom log named "VMware_CL" for ESXiHost1 syslog.

  1. After setup is finished, go to the OMS Settings page, and see whether your vCenter server is on-boarded.
  2. Next, set up the OMS Custom field for certain records. For customer field instructions, see Custom fields in Log Analytics.
VMwareHost_CF ESXi Hostname
VMwarePN_CF VMware Application Name ( vmkernel, vmkwarning, vobd, hostd, etc.)

After you have competed the setup, you should be able to run a simple query against the syslog.

Example query strings

In day-to-day operations, you would like to understand the events that are happening in your environment. Here, I added some queries that can provide you with top 10 VMware events and trends, disk warning trends, VM creation/deletion counts, storage latency, etc. You can reuse these queries for other query use cases as well.

These queries can be charted and placed on an OMS dashboard. For details about “My Dashboard”, see Create a custom dashboard in Log Analytics.

Top 10 VMware event counts

Top 10 Event charting Type=VMware_CL  | measure count() by VMwarePN_CF | top 10

Graph of top ten event charting.

Trend of the event counts

Event Trend Hourly Interval Type=VMware_CL |  measure countdistinct(TimeGenerated) by VMwareHost_CF Interval 1HOUR

Graph of trends of event counts.

Disk warning seen on a certain ESXi host within certain interval

Hourly Interval Charting Type=VMware_CL VMwareHost_CF="yourESXihostname " VMwarePN_CF=smartd "warn"  | measure count() interval 1HOUR
Daily Interval Charting Type=VMware_CL VMwareHost_CF="yourESXihostname " VMwarePN_CF=smartd "warn"  | measure count() interval 1DAY

Graph of disk warning seen on a certain ESXi host within certain interval.

Disk temperature warning count chart

Hourly Interval disk temperature on ESXi above threshold Type=VMware_CL VMwareHost_CF="yourESXihostname" VMwarePN_CF=smartd ("warn" and "above temperature") | measure count() interval 1HOUR

Graph of disk temperature warning count chart.

VMs powered off counts per ESXi Host in last 24 hours

Daily Interval Chart Type=VMware_CL  ("is powered off") VMwarePN_CF=Hostd   TimeGenerated:[NOW-1DAY..NOW] | measure count () by VMwareHost_CF

Graph of VMs powered off counts per ESXi Host in last 24 hours.

Count of created VMs in last 24 hours

Daily Interval Chart Type=VMware_CL ("Created virtual machine") TimeGenerated:[NOW-1DAY..NOW] | measure countdistinct(TimeGenerated) by VMwareHost_CF

Graph of count of created VMs in last 24 hours.

Count of deleted VMs in last 24 hours

Daily Interval Chart Type=VMware_CL VMwarePN_CF=Hostd ("removed") TimeGenerated:[NOW-1DAY..NOW] | measure countdistinct(TimeGenerated) by VMwareHost_CF

Graph of count of deleted VMs in last 24 hours.

Storage latency warning per ESXi Host in last 24 hours

Daily Interval Chart Type=VMware_CL  ("latency")   TimeGenerated:[NOW-1DAY..NOW] | measure count() by VMwareHost_CF

Graph of storage latency warning per ESXi Host in last 24 hours.

Example alerting

OMS has an alerting capability that uses search query results. Within the OMS alert rule UI, you can set a time window for when the search query should run and place a threshold to generate alerts. The following query will not have the threshold counts. For more information about how to set up alerting, see Alerts in Log Analytics.

Screenshot of the schedule options.

As a default. I would recommend setting the threshold to 3. After you set up the alerting on OMS, you see an email notification.

Example of an email notification.

Here are some example queries that you can set for problem alerting.

Alerting on multiple VM powered off in a certain time interval

Alerting Multiple VM powered off Type=VMware_CL ("is powered off") VMwareHost_CF="yourESXihostname"

Alerting on storage temperature high

Alert on the high temperature query Type=VMware_CL  VMwarePN_CF=smartd ("warn" and "above temperature")

Alerting on disk warning

Disk Warning Alerting Type=VMware_CL  VMwarePN_CF=smartd "warn"

Alerting on Storage Capacity coming close to consumption ESXi Host

Disk Space Alerting Type=VMware_CL ("space left on device")

vCenter Server Shutdown

On Windows Server, vCenter Server will be logged as application event logs. OMS Windows Agent already captures the events for vCenter Server. For this query, the interval for alerting should be once every interval.

vCenter Shutting down EventLog=Application Source="VMware VirtualCenter Server" "shutdown"

Get a free Microsoft Operations Management Suite (#MSOMS) subscription so that you can test the new alerting features. You can also get a free subscription for Microsoft Azure.

I invite you to follow me on Twitter and the Microsoft OMS Facebook site. If you want to learn more about Windows PowerShell, visit the Hey, Scripting Guy Blog. If you have any questions, send email to me at or provide your suggestion at OMS UserVoice. I wish you a wonderful day, and I’ll see you tomorrow.

Keiko Harada
Microsoft Operations Management Team


Comments (10)
  1. luki says:

    Is there any chance to monitoring in OMS –> Vmware Environment by Operations Manager for Vmware?


    1. Keiko Harada says:

      Hello Luki, at this moment, we do not have OMS monitor with Operations Manager for VMware. Please add your suggestion to the OMS UserVoice so we can track and review your suggestion. Again thank you for the comment.

      1. luki says:

        Thx for reply.

  2. Richard says:

    Hi Guys,

    There is another great way to monitor VMware with OMS (and SCOM). Just have a look at the link below.

    From experience I can tell that they have a great product and give away free trials to people who want to try these solutions.


  3. Jayme says:

    Trying to setup OMS in this exact same manner. Syslog is pushing data to vcenter in the default collector folder. All I am getting in OMS is Unknown type ‘VMware_CL’ 9 times. I cant find much info at all for troubleshooting OMS errors

    1. Keiko says:

      Hi Jayme, I am not sure whether you saw the blog Are you doing this? Also if you can provide more detail, please send email to This is just a DIY blog and I created a new one with you will need 1.2.0-75 omsagent installed to enable the VMware Solution. This blog and VMware Solution released in September is does not work together. regards,

  4. Guillaume says:

    Hi, i’ve installed MMA on Linux server which listen on with TCP to capt syslog from ESXI (no vCenter Server) and i have the error “Unknown type ‘VMware_CL’ ” 9 times per day.
    Someone can help me ?

    1. Keiko says:

      Sure we can help. Please send email to with your steps of what you did and what error you are seeing. Please make sure you are using 1.2.0-75 version of the omsagent. regards,

  5. Harvey says:

    Do you have a solution for Linux? That would be helpful.

    1. Keiko says:

      Hi Harvey, we do. We created a VMware solution which pre-populates the fields. Please refer to the blog Please check that out and try it. Thanks!!

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