There's a new mob in town, FDM MOB for ESXi 5

That's right, vSphere is not the only one with a MOB, the new FDM (Fault Domain Manager) feature also includes a MOB view on an ESXi 5.0 hosts that is part of an FDM/HA enabled cluster. I originally noticed this new URL while parsing through the systems logs an ESXi host to get a better understanding of the startup process and found this little nugget. This page contains private APIs that are currently not exposed for public consumption with respect to FDM service, please use at your own risk.

To access the FDM MOB, you will need to point your browser to the following URL:

https://[esxi5_hostname]/mobfdm

Here is a screenshot of the main summary page:

On the summary page, you have some basic information about the particular host in question, one interesting property is the "clusterState" which will be either a master or slave node, this can be useful in troubleshooting if you do not have access to vCenter

The are two interesting methods that can provide some useful information: RetrieveClusterInfo and RetrieveHostList which should be pretty self explanatory in what they will be doing.

To generate the URL for the RetrieveClusterInfo you will need to point your browser to the following URL:

https://[esxi5_hostname]/mobfdm/?moid=fdmService&method=retrieveClusterInfo

As you can see from the screenshot, it provides a summary for the particular ESXi host within the FDM cluster, including the masterID, this ID will be useful when we call the other method to identify the master node in the FDM cluster.

To generate the URL for the RetrieveHostList you will need to point your browser to the following URL:

https://[esxi5_hostname]/mobfdm/?moid=fdmService&method=retrieveHostList

This method extracts all hosts from the FDM cluster and provides quite a bit of information about each host including the hostname and also the hostID. You can now translate ID found in the last method to identify the master node of the FDM cluster.

When you login to the FDM MOB for an ESXi host that is a master node in the cluster, the page will look slightly different with even more details including all slave nodes and protected VMs within the cluster.

As you can see this can be a useful tool for quickly identifying the master and slave nodes within an FDM cluster without going to your vCenter Server.

You can also get this information within the ESXi Shell, there is a hostlist file in an XML format that you can view the same information found in the RetrieveClusterInfo method located in /etc/opt/vmware/fdm/hostlist

~ # cat /etc/opt/vmware/fdm/hostlist
host-70
FB43716F-84A5-45AD-A5BB-F08BC64148DF-14-5db552f-vcenter50-133host-205esxi50-2.primp-industries.com58:C9:81:F1:3D:A1:47:B8:7A:C0:33:93:71:3A:B9:A1:51:AD:25:51172.30.0.7300:19:bb:26:25:8e00:19:bb:26:25:7e/vmfs/volumes/664220b6-9628e4e3/vmfs/volumes/f0613bc2-56e80c59443host-70esxi50-1.primp-industries.com25:C3:FE:23:B1:DB:5C:F8:94:13:A3:CD:B0:DC:EA:51:72:F1:53:4F172.30.0.7200:1f:29:c9:48:e200:1f:29:c9:48:f8/vmfs/volumes/664220b6-9628e4e3/vmfs/volumes/f0613bc2-56e80c59443

You also get the details of RetrieveHostList and cleaner output of the FDM host using the following script: /opt/vmware/fdm/fdm/prettyPrint.sh. The script can accept three different arguments: hostlist, clusterconfig and compatlist

Here is a screenshot of the hostlist:

Here is a screenshot of the clusterconfig:

Here is screenshot the compatlist: