Domain Time Sync – OS Test
Time synchronization is one of the most important dependencies of windows. A time protocol is responsible for determining the best available time information and converging the clocks to ensure that a consistent time is maintained across systems. By default, windows support a tolerance of plus or minus five minutes for clocks. If the time variance exceeds this setting, clients will be unable to authenticate and in the case of domain controllers, replication will not occur. It implements a time synchronization system based on Network Time Protocol (NTP).
NTP is a fault-tolerant, highly scalable time protocol and it is used for synchronizing computer clocks by using a designated reference clock. A reference clock is some device or machinery that spits out the current time. The special thing about these things is accuracy. Reference clocks must be accurately following some time standard. NTP will compute some additional statistical values based on the current time reported by the reference clock, which will describe the quality of time it sees. Among these values are: offset (or phase), jitter (or dispersion), frequency error, and stability. Thus each NTP server will maintain an estimate of the quality of its reference clocks and of itself.
This test reports the time difference between the reference clock and that of the target environment, and thus helps assess the quality of time seen by the Windows VM. With the help of this test, you can also easily determine whether the reference time changed recently.
Note:
This test reports metrics for Windows VMs only.
This test is disabled by default. To enable the test, go to the enable / disable tests page using the menu sequence : Agents -> Tests -> Enable/Disable, pick Oracle VirtualBox as the desired Component type, set Performance as the Test type, choose the test from the disabled tests list, and click on the < button to move the test to the ENABLED TESTS list. Finally, click the Update button.
Target of the test : An Oracle VirtualBox
Agent deploying the test : An internal/remote agent
Outputs of the test : One set of results for each powered-on Windows desktop/currently logged-in user on the VirtualBox monitored.
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 number at which the specified Host listens to. |
Oracle Hypervisor |
Specify the name of the user who has the right to access the VirtualBox via SSH. |
Oracle Hypervisor Password |
Provide the password of the oracle hypervisor user. |
Confirm Password |
Confirm the password by retyping it here. |
Sudocmd |
This test executes certain privileged VDA (Virtual Desktop Access) commands to pull out the desired metrics from the VirtualBox. To enable the test to run these commands, you first need to install a sudo package on the VirtualBox host. The procedure for installing this package is detailed in Pre-requisites for Auto-Discovering VMs and Obtaining their Outside View. Once the package is installed, you need to specify the full path to the install directory of the sudo package in the Sudocmd text box. |
Ignore VMs Inside |
Administrators of some high security virtualized 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 an Oracle VirtualBox 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. |
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. |
Ignore WINNT |
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. |
Inside View Using |
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 (Windows) on every Windows VM; this VM agent allows the eG agent to collect “inside view” metrics from the Windows VMs without domain administrator rights. Refer to Configuring the eG Agent to Obtain the Inside View of Windows VMs, using the eG VM Agent for more details on the eG VM Agent. 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. |
Domain, |
By default, this test connects to each virtual guest remotely and attempts to collect “inside view” metrics. In order to obtain a remote connection, the test must be configured with user privileges that allow remote communication with the virtual guests. The first step towards this is to specify the Domain within which the virtual guests reside. The admin user and admin password will change according to the Domain specification. Discussed below are the different values that the domain parameter can take, and how they impact the admin user and admin password specifications:
|
Report By User |
While monitoring a VirtualBox, the Report By User flag is set to Yes by default, indicating that by default, the guest operating systems on the VirtualBox are identified using the login of the user who is accessing the guest OS. In other words, this test will, by default, report measures for every username_on_virtualmachinename. If this flag is set to No, then the guests will be identified using the host name of the guest OS. In this case, the test will report measures for every virtualmachinename. |
Report Powered OS |
This flag becomes relevant only if the Report By User flag is set to ‘Yes’. If the Report Powered OS flag is set to Yes (which is the default setting), then this test will report measures for even those VMs that do not have any users logged in currently. Such guests will be identified by their virtualmachine name and not by the username_on_virtualmachinename. On the other hand, if the Report Powered OS flag is set to No, then this test will not report measures for those VMs to which no users are logged in currently. |
Measurement | Description | Measurement Unit | Interpretation |
---|---|---|---|
NTP offset |
Indicates the time difference between the local clock and the designated reference clock. |
Secs |
For a tiny offset, NTP will adjust the local clock; for small and larger offsets, NTP will reject the reference time for a while. In the latter case, the operating system's clock will continue with the last corrections effective while the new reference time is being rejected. After some time, small offsets (significantly less than a second) will be slewed (adjusted slowly), while larger offsets will cause the clock to be stepped (set anew). Huge offsets are rejected, and NTP will terminate itself, believing something very strange must have happened. |