The VmhDiskSpaceTest monitors the space usage of every disk partition (including VMFS partitions) on an ESX server host.

The default parameters associated with this test are as follows:

• The TEST PERIOD list box helps the user to decide how often this test needs to be executed.

• In the HOST text box, the host name of the server for which the test is to be configured has to be specified.

• Specify the PORT at which the above-mentioned HOST listens. By default, this is NULL.

• In order to enable the test to extract the desired metrics from a target ESX server, you need to configure the test with an ESX USER and ESX PASSWORD. The user credentials to be passed here depend upon the mechanism used by the eG agent for discovering the VMs on the target ESX server and collecting performance statistics from it. These monitoring/discovery methodologies and their corresponding configuration requirements have been discussed hereunder:

  • Monitoring using the VmPerl API/CLI: By default, the eG agent uses the VmPerl API/ESX CLI for monitoring an ESX server and discovering the guests executing on it. Since this monitoring approach is very straight-forward and requires no additional configuration, the ESX USER and ESX PASSWORD parameters are set to none by default.
  • VM discovery using the web services interface of the ESX server: Starting with ESX server 3.0, a VMware ESX server offers a web service interface using which the eG agent discovers the guest operating systems on a physical ESX host. The VMware VI SDK is used by the agent to implement the web services interface. To use this interface for discovering the VMs, this test should be configured with an ESX USER who has "Read-only" privileges to the target ESX server. By default, the root user is authorized to execute the test. However, it is preferable that you create a new user on the target ESX host and assign the "Read-only" role to him/her. The steps for achieving this have been elaborately discussed in the Monitoring VMware Infrastructures document.

  • VM discovery using the vCenter in the target environment: By default, the eG agent connects to each ESX server and discovers the VMs executing on it. While this approach scales well, it requires additional configuration for each server being monitored. For example, separate user accounts may need to be created on each server for read-only access to VM details. While monitoring large virtualized installations however, the agents can be optionally configured to perform discovery using the VM information already collected by the vCenter installation that may be in use in the environment. In this case therefore, the ESX USER and ESX PASSWORD that you specify should be that of an Administrator or Virtual Machine Administrator in vCenter. However, if, owing to security constraints, you prefer not to use the credentials of such users, then, you can create a special role on vCenter that allows users to View and Terminate sessions, and assign this role to a local/domain user. Refer to the Monitoring VMware Infrastructures document for the corresponding procedure.

  When the eG agent is started/restarted, it first attempts to connect to the vCenter server and terminate all existing sessions for the user whose credentials have been provided for the tests. This is done to ensure that unnecessary sessions do not remain established in the vCenter server for the session timeout period. Ideally, you should create a separate user account with the required credentials and use this for the test configurations. If you provide the credentials for an existing user for the test configuration, when the eG agent starts/restarts, it will close all existing sessions for this user (including sessions you may have opened using the Virtual Infrastructure client). Hence, in this case, you may notice that your VI client sessions are terminated when the eG agent starts/restarts.

• Confirm the password by retyping it in the CONFIRM PASSWORD text box.

• By default, the ESX server is SSL-enabled. Accordingly, the SSL flag is set to Yes by default. This indicates that the eG agent will communicate with the ESX server via HTTPS by default. On the other hand, if the eG agent has been configured to use the VMPerl API or CLI for guest discovery (i.e., if the ESX USER parameter is set to none), then the status of the SSL flag is irrelevant.

  Like the ESX sever, the vCenter is also SSL-enabled by default. If you have chosen to use the vCenter for guest discovery, then you have to set the SSL flag to Yes.

• By default, in most virtualized environments, the ESX server and vCenter listen on port 80 (if not SSL-enabled) or on port 443 (if SSL-enabled). This implies that while monitoring an SSL-enabled ESX server directly, the eG agent, by default, connects to port 443 of the ESX server to pull out metrics, and while monitoring a non-SSL-enabled ESX server, the eG agent connects to port 80. Similarly, while monitoring an ESX server via an SSL-enabled vCenter, the eG agent connects to port 443 of vCenter to pull out the metrics, and while monitoring via a non-SSL-enabled vCenter, the eG agent connects to port 80 of vCenter. Accordingly, the WEBPORT parameter is set to 80 or 443 depending upon the status of the SSL flag. In some environments however, the default ports 80 or 443 might not apply. In such a case, against the WEBPORT parameter, you can specify the exact port at which the ESX server or vCenter in your environment listens so that the eG agent communicates with that port.

• If you have chosen to use the vCenter for discovering the guests on an ESX server and have configured the ESX USER and ESX PASSWORD accordingly, then, provide the IP address of the vCenter host in the VIRTUAL CENTER text box.

  On the other hand, if you want the eG agent to behave in the default manner - i.e., communicate with each ESX server for VM information - then set the VIRTUAL CENTER parameter to 'none'. In this case, the ESX USER and ESX PASSWORD parameters can either be set to none or can be configured with the credentials of a user who has at least 'Read-only' privileges to the target ESX server.

• The VMware ESX server 3.5 (or above) denies 'normal' ESX users access to VMFS disk partitions and related usage statistics. This implies that the VmhDiskSpaceTest will require root user privileges to extract space usage statistics from a VMware ESX server 3.5 (or above). Therefore, in order to automatically grant root user privileges to the eG agent at run time, the USESUDO flag is set to Yes by default.

• If multiple components of the same component type are awaiting configuration, then an APPLY TO OTHER COMPONENTS check box will appear in this page. Clicking on this check box will allow you to apply the configuration to all/selected components of that type.

• Once the necessary values have been provided, clicking on the Update button will register the changes made.

When changing the configuration for specific servers, a “*” beside the text box corresponding to the parameter signifies that these values have to be manually configured by the user. The parameter values that require to be configured will typically be prefixed with a “$” or contain a series of “*”. A value of "none" in the parameter value indicates that the corresponding parameter value can be changed if required.