This blog post is written by Elavarasan Selvaraj and Krishnaprasad K from Dell Operating System team. 

The Common Information Model (CIM) interface on an ESXi host provides a way of remotely monitoring the hardware health of your hosts via the Web-Based Enterprise Management (WBEM) protocol. It builds on a standard HTTP(S) API, allowing secure SSL/TLS protected authentication and communication between the host and the management stations. From ESXi 6.5 onwards, VMware introduced a new namespace named as ‘wbem’ as an extension for esxcli which controls the services such as sfcbd and wsman. From ESXi 6.5 onwards, sfcdb and wsman are disabled by default as wbem is kept to false by default.

The wbem services gets enabled automatically when an OEM provider VIB is installed.  For example when Dell OpenManage systems management software is installed on ESXi 6.5, you may see that the services such as sfcbd and wsman are started automatically. This blog detail on the options wbem provides which can help understand and troubleshooting CIM related issues. 

Wbem Service command details

This section summarizes some of the options provided by wbem which would be helpful for users relying on CIM systems management stack with in ESXi to monitor/manage their systems. 

Below is what you see on a newly installed ESXi 6.5 in terms of the service status. 

~] esxcli system wbem get

   Authorization Model: password

   Enabled: false

   Loglevel: warning

   Port: 5989

   WSManagement Service: true

You may see that the service is disabled by default. This also mean that sfcbd and wsman services are turned off by default.

~] /etc/init.d/sfcbd-watchdog status

sfcbd is not running

~] /etc/init.d/wsman status

openwsmand is not running

After enabling wbem, you may observe that sfcbd and wsman are turned on.

~] esxcli system wbem set -e 1

 

~] /etc/init.d/sfcbd-watchdog status

sfcbd is running

 

~] /etc/init.d/wsman status

openwsmand is running

 

Now, let's look into some of the options provided by wbem. Below is the help menu which detail various command parameters. 

 ~] esxcli system wbem set --help

Usage: esxcli system wbem set [cmd options]

 Description:

  set                   This command allows the user to set up ESX CIMOM agent.

 Cmd options:

  -a|--auth=<str>       Specify how to authorize incoming requests. Values are password, certificate, password is by default. Changes take effect when --enable is

                        specified.

  -e|--enable           Start or stop the WBEM services (sfcbd, openwsmand). Values: [yes|no, true|false, 0|1]

  -l|--loglevel=<str>   Syslog logging level: debug|info|warning|error

  -p|--port=<long>      Set the TCP port on which the CIMOM listens for requests. The default is 5989

  -r|--reset            Restore the WBEM configuration to factory defaults

  -W|--ws-man           Enable or disable the WS-Management service (openwsmand). Enabled by default. Changes take effect when --enable is specified.

 

~] esxcli system wbem -h

Usage: esxcli system wbem {cmd} [cmd options]

Available Namespaces:
provider

Available Commands:
get Display WBEM Agent configuration.
set This command allows the user to set up ESX CIMOM agent.

There is an extension available for wbem (named as provider) as well which is useful to understand the providers that are registered to sfcbd and enabled. Below is a sample command output taken from an ESXi 6.5 host with default providers. When Dell OpenManage is installed, you may see an additional entry named as 'OpenManage' to the below. 

~] esxcli system wbem provider list

Name Enabled Loaded
---------------- ------- ------
sfcb_base true true
vmw_base true true
vmw_hdr true true
vmw_hhrcwrapper true true
vmw_iodmProvider true true
vmw_kmodule true true
vmw_omc true true
vmw_pci true true
vmw_vi true true

The below command provides an option to enable/disable individual providers registered to sfcb. 

~] esxcli system wbem provider set <-e | --enable> <yes|no, true | false, 0|1>

Few other useful commands related to wbem are the following. 

~] esxcli system wbem set -a | --auth=<str>

The authentication method defines how the incoming requests are authenticated from the external HTTPs APIs. Password and certificate are the two options available. 

~] esxcli system wbem set -e | --enable true|false     (sfcbd, openwsmand)

~] esxcli system wbem set -W | --ws-man true|false (openwsmand)

This allows the administrator to enable/disable wsman service specifically. 

~] esxcli system wbem set -l | --log-level=<str> debug|info|warning| error

 This is an important parameter available for wbem. This is a useful option for troubleshooting CIM issues.

           ~] esxcli system wbem set -p | --pot=<long>  

Setting the TCP port for CIMOM communication listens the request from outside HTTPs API. By default it's set to 5989. You may use this parameter only if there is a requirement to change the default port used. 

~] esxcli system wbem set -r | --reset

This command resets the wbem configuration to the default.  

Dell systems management support for ESXi 6.5

                DellEMC provides an inband management tool known as OpenManage in which it provides two specific solutions named as Server Administrator (OMSA) and iDRAC Service Module(iSM). Dell released an OMSA version of 8.5 supported for ESXi 6.5 which is a test and document supported version. The iSM version is yet to be out for ESXi 6.5.