Sometimes, a VM could be in a powered-on state, but the failure of the VM operating system or any fatal error in VM operations could have rendered the VM inaccessible to users. In order to enable administrators to promptly detect such 'hidden' anomalies, the eG agent periodically runs a connectivity check on each VM using the VmAccess Test, and reports whether the VM is accessible over the network or not.

This page depicts the default parameters that need to be configured for the VmAccessTest.

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

• To enable the eG agent to connect to the XenServer API for collecting statistics of interest, this test should login to the XenServer as a root user. Provide the name of the root user in the XEN USER text box. Root user privileges are mandatory when monitoring a XenServer 5.5 (or lesser). However, if you are monitoring XenServer 5.6 (or above) and you prefer not to expose the credentials of the root user, then, you have the option of configuring a user with pool-admin privileges as the XEN USER.

• The password of the specified XEN USER needs to be mentioned in the XEN PASSWORD text box.

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

• By default, the Xen Server is not SSL-enabled. This indicates that by default, the eG agent communicates with the XenServer using HTTP. Accordingly, the SSL flag is set to No by default. If you configure the XenServer to use SSL, then make sure that the SSL flag is set to Yes, so that the eG agent communicates with the XenServer using HTTPS. Note that a default SSL certificate comes bundled with every XenServer installation. If you want the eG agent to use this default certificate for communicating with an SSL-enabled XenServer, then no additional configuration is required. However, if you do not want to use the default certificate, then you can generate a self-signed certificate for use by the XenServer. In such a case, you need to explicitly follow the broad steps given below to enable the eG agent to communicate with the XenServer via HTTPS:

1. Obtain the server-certificate for the XenServer
2. Import the server-certificate into the local certificate store of the eG agent

For an elaborate discussion on each of the above-mentioned steps, refer to the Troubleshooting section in the Monitoring Xen Servers document.

• By default, this test communicates with every VM remotely and extracts “inside view” metrics. Therefore, by default, the INSIDE VIEW USING flag is set to Remote connection to VM (Windows). Typically, to establish this remote connection with Windows VMs in particular, eG Enterprise requires that the eG agent be configured with domain administrator privileges. In high-security environments, where the IT staff might have reservations about exposing the credentials of their domain administrators, this approach to extracting “inside view” metrics might not be preferred. In such environments therefore, eG Enterprise provides administrators the option to deploy a piece of software called the eG VM Agent on every Windows VM; this VM agent allows the eG agent on the service console to collect "inside view" metrics from the Windows VMs without domain administrator rights.To ensure that the “inside view” of Windows VMs is obtained using the eG VM Agent, set the INSIDE VIEW USING flag to eG VM Agent (Windows). Once this is done, you can set the DOMAIN, ADMIN USER, and ADMIN PASSWORD parameters to none.

• By default, in most virtualized environments, the XenServer listens on port 80 (if not SSL-enabled) or on port 443 (if SSL-enabled). This implies that while monitoring an SSL-enabled XenServer, the eG agent, by default, connects to port 443 of the server to pull out metrics, and while monitoring a non-SSL-enabled XenServer, the eG agent connects to port 80. 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 XenServer in your environment listens so that the eG agent communicates with that port.

• Administrators of some high security XenServer environments might not have permissions to internally monitor one/more VMs. The eG agent can be configured to not obtain the ‘inside view’ of such ‘inaccessible’ VMs using the IGNORE VMS INSIDE VIEW parameter. Against this parameter, you can provide a comma-separated list of VM names, or VM name patterns, for which the inside view need not be obtained. For instance, your IGNORE VMS INSIDE VIEW specification can be: *xp,*lin*,win*,vista. Here, the * (asterisk) is used to denote leading and trailing spaces (as the case may be). By default, this parameter is set to none indicating that the eG agent obtains the inside view of all VMs on a XenServer host by default.

  Note:

  While performing VM discovery, the eG agent will not discover the operating system of the VMs configured in the IGNORE VMS INSIDE VIEW text box.

• Administrators of some virtualized environments may not want to monitor some of their less-critical VMs - for instance, VM templates - both from ‘outside’ and from ‘inside’. The eG agent in this case can be configured to completely exclude such VMs from its monitoring purview. To achieve this, provide a comma-separated list of VMs to be excluded from monitoring in the EXCLUDE VMS text box. Instead of VMs, VM name patterns can also be provided here in a comma-separated list. For example, your EXCLUDE VMS specification can be: *xp,*lin*,win*,vista. Here, the * (asterisk) is used to denote leading and trailing spaces (as the case may be). By default, this parameter is set to none indicating that the eG agent obtains the inside and outside views of all VMs on a virtual host by default. By providing a comma-separated list of VMs/VM name patterns in the EXCLUDE VMS text box, you can make sure the eG agent stops collecting ‘inside’ and ‘outside’ view metrics for a configured set of VMs.

• By default, the eG agent does not support the inside view for VMs executing on Windows NT operating systems. Accordingly, the IGNORE WINNT flag is set to Yes by default.

• The size of packets used for the test (in bytes) should be specified in the PACKETSIZE text box.

• The number of packets to be transmitted during the test should be specified in the PACKETCOUNT

• How long after transmission should a packet be deemed lost (in seconds) should be specified in the TIMEOUT text box.

• PACKETINTERVAL represents the interval (in milliseconds) between successive packet transmissions during the execution of the network test for a specific target.

• By default, the REPORTUNAVAILABILITY flag is set to No. This implies that, by default, the test will not report the unavailability of network connection to any VM. In other words, if the Network availability measure of this test registers the value 0 for any VM, then, by default, this test will not report any measure for that VM; under such circumstances, the corresponding VM name will not appear as a descriptor of this test. You can set this flag to Yes, if you want the test to report and alert you to the unavailability of the network connection to a VM.

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

When changing default configurations of tests, the values with "$" indicate variables that will be replaced by the eG system according to the specific server being managed - for instance, $hostName is the host/nickname of the target host, $port is the port number of the server being monitored. E.g., for a server xyz:80, $hostName will be changed automatically by the eG manager to "xyz" and $port will be changed to "80" when configuring a test.