Agents Administration - Tests
 

Default Parameters for XenSnapshotTest

This test tracks the number and size of snapshot files for a VM, the detailed diagnosis reveals the size of each snapshot, thus enabling administrators to quickly spot those snapshot files that are too large in size.

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

  • 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:

    • Obtain the server-certificate for the XenServer
    • 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, 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.
  • By default, 15 days is set as AGELIMIT. This implies that the test will report all those snapshots that are more than 15 days old as Old snapshots. If required, you can change the AGELIMIT.
  • By default, 10000 KB is set as the SIZELIMIT. This implies that the test will report all those snapshots that have a size more than 10000 KB as Large snapshots. If required, you can change the SIZELIMIT.
  • By default, the detailed diagnosis of the Number of snapshots measure provides details of all the snapshots on a VM. Likewise, the detailed diagnosis of the Large snapshot count and Aged snapshot count measures provides the details of all large-sized snapshots and old snapshots, respectively. This is why, the SHOW TOP parameter is set to All by default. To make sure that the detailed diagnosis of the each of these measures lists, for instance, only the top-5 snapshots in terms of size/age (as the case may be), then, specify 5 against SHOW TOP. If this is done, then:

    • The detailed diagnosis of the Number of snapshots and Aged snapshot count measures will provide the details of only the top-5 snapshots in terms of age.
    • The detailed diagnosis of the Large snapshot count measure will provide the details of only the top-5 snapshots in terms of size.
    In the same way, you can specify any non-zero value against SHOW TOP to view only that many top snapshots in the detailed diagnosis.

  • 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.

  • DD FREQUENCY refers to the frequency with which detailed diagnosis measures are to be generated for this test. For instance, if you set to 1:1, it means that detailed measures will be generated every time this test runs, and also every time the test detects a problem.

  • 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.