Xen VM Tools Status Test

Citrix Hypervisor Tools, the Citrix Hypervisor paravirtualization tools, provide high speed I/O for enhanced disk and network performance. Citrix Hypervisor Tools must be installed on each virtual machine (Windows and Linux) in order to use the xe CLI or XenCenter; moreover, VM performance will significantly deteriorate unless the tools are installed.

 Without the tools installed, you will not be able to do any the following:

  1. Cleanly shut down, reboot or suspend a VM.
  2. View VM performance data in XenCenter.
  3. Migrate a running VM (via XenMotion).
  4. Create quiesced snapshots or snapshots with memory (checkpoints), or revert to snapshots.
  5. Adjust the number of vCPUs on a running Linux VM (Windows VMs require a reboot for this to take effect).

Using the Xen VM Tools Status test, you can ascertain whether the Citrix Hypervisor tools are installed or not on a VM.

Target of the test : A Citrix Hypervisor host

Agent deploying the test : An internal/remote agent

Outputs of the test : One set of results for each VM on the target Citrix Hypervisor host

Configurable parameters for the test
Parameter Description

Test period

How often should the test be executed.

Host

The host for which the test is to be configured.

Port

The port at which the specified host listens. By default, this is NULL.

Xen User, Xen Password and Confirm Password

To enable the eG agent to connect to the XenServer API for collecting statistics of interest, this test should login to the target hypervisor 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 below). 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. If you do not want to expose the credentials of a root/pool-admin user, then you can configure the tests with the credentials of a Xen User with Read-only privileges to the XenServer. However, if this is done, then the Xen Uptime test will not run, and the Xen CPU and Xen Memory tests will not be able to report metrics for the control domain descriptor. To avoid such an outcome, do the following before attempting to configure the eG tests with a Xen User who has Read-only privileges to the Citrix Hypervisor:

  • Modify the target hypervisor's configuration in the eG Enterprise. For this, follow the Infrastructure -> Components -> Add/Modify menu sequence, pick Citrix Hypervisor as the Component type, and click the Modify button corresponding to the target hypervisor.
  • In the MODIFY COMPONENT DETAILS page that then appears, make sure that the os is set to Xen and the Mode is set to SSH.
  • Then, in the same page, proceed to provide the User and Password of a user who has the right to connect to the XenServer console via SSH.
  • Then, click the Update button to save the changes.

Once this is done, you can configure the eG tests with the credentials of a Xen User with Read-only privileges.

The password of the specified Xen User needs to be mentioned in the Xen Password text box.

Then, confirm the Xen Password by retyping it in the Confirm Password text box.

SSL

By default, the Citrix Hypervisor is not SSL-enabled. This indicates that by default, the eG agent communicates with the target hypervisor using HTTP. Accordingly, the SSL flag is set to No by default. If you configure the target hypervisor to use SSL, then make sure that the SSL flag is set to Yes, so that the eG agent communicates with the target hypervisor using HTTPS. Note that a default SSL certificate comes bundled with every Citrix Hypervisor installation. If you want the eG agent to use this default certificate for communicating with an SSL-enabled Citrix Hypervisor, 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 target hypervisor. In such a case, you need to explicitly follow the broad steps given below to enable the eG agent to communicate with the target hypervisor via HTTPS:

  • Obtain the server-certificate for the Citrix Hypervisor
  • Import the server-certificate into the local certificate store of the eG agent

For a detailed discussion on each of these steps, refer to the Troubleshooting section of this document.

Exclude VMs

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.

Webport

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

DD Frequency

Refers to the frequency with which detailed diagnosis measures are to be generated for this test. The default is 1:1. This indicates that, by default, detailed measures will be generated every time this test runs, and also every time the test detects a problem. You can modify this frequency, if you so desire. Also, if you intend to disable the detailed diagnosis capability for this test, you can do so by specifying none against DD FREQUENCY.

Detailed Diagnosis

  1. To make diagnosis more efficient and accurate, the eG suite embeds an optional detailed diagnostic capability. With this capability, the eG agents can be configured to run detailed, more elaborate tests as and when specific problems are detected. To enable the detailed diagnosis capability of this test for a particular server, choose the On option. To disable the capability, click on the Off option.

    The option to selectively enable/disable the detailed diagnosis capability will be available only if the following conditions are fulfilled:

    • The eG manager license should allow the detailed diagnosis capability
    • Both the normal and abnormal frequencies configured for the detailed diagnosis measures should not be 0.
   
Measurements made by the test
Measurement Description Measurement Unit Interpretation

Is Xen tools installed?:

Indicates whether/not XenServers Tools has been installed on this VM.

 

If XenServer Tools is installed on a VM, this measure will report the value Yes. On the other hand, if XenServer Tools is not installed on a VM, this measure will report the value No.

The numeric values that correspond to each of the measure values discussed above have been detailed in the table below:

Measure Value Numeric Value

Yes

1

No

0

Note:

By default, this measure reports Yes or No to indicate whether XenServer Tools is installed on a VM or not. The graph of this measure however, represents the same using the numeric equivalents only – i.e., 0 or 1.

Is Xen tools up to date?:

Indicates whether the latest version of XenServer Tools has been installed on this VM.

 

If the latest version of XenServer Tools is installed on a VM, this measure will report the value Yes. On the other hand, if an older/obsolete version of XenServer Tools is installed on a VM, this measure will report the value No.

The numeric values that correspond to each of the measure values discussed above have been detailed in the table below:

Measure Value Numeric Value
Yes 1
No 0

Note:

By default, this measure reports Yes or No to indicate the version of XenServer Tools installed on a VM. The graph of this measure however, represents the same using the numeric equivalents only – i.e., 0 or 1.