Uptime - VM Test

In most virtualized environments, it is essential to monitor the uptime of VMs hosting critical server applications in the infrastructure. By tracking the uptime of each of the VMs, administrators can determine what percentage of time a VM has been up. Comparing this value with service level targets, administrators can determine the most trouble-prone areas of the virtualized infrastructure.

In some environments, administrators may schedule periodic reboots of their VM. By knowing that a specific VM has been up for an unusually long time, an administrator may come to know that the scheduled reboot task is not working on a VM.

This test included in the eG agent monitors the uptime of each VM on an RHEV Hypervisor. 

Target of the Test: A RHEV Hypervisor

Agent running the test: A remote agent

Output of the test: One set of results for every VM on an RHEV Hypervisor .

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.

RHEL MGR Host,
RHEL MGR Port,
RHEL MGR Domain,
RHEL MGR User
RHEL MGR Password

To auto-discover the VMs on a target RHEV hypervisor and obtain the outside view of the performance of each VM, the eG agent needs to connect to the RHEV Manager that manages the target RHEV hypervisor. To enable the eG agent to obtain the outside view, you need to configure the test with the following:

  • RHEL MGR Host - The IP address/host name of the RHEV manager that the eG agent should connect to.
  • RHEL MGR Port - The port number at which the said RHEV manager listens.
  • RHEL MGR Domain - The domain to which the RHEV manager belongs.
  • RHEL MGR User and RHEL MGR Password - The credentials of a user with read-only access to the Restful API on the RHEV manager. To know how to create a read-only role and assign it to a user, follow the steps detailed in Configuring the eG Agent to use the RESTful APIs on the RHEV Manager to Obtain the “Outside View”.

If the RHEV hypervisor being monitored was discovered via an RHEV manager, then the IP address, port number, domain name, and user credentials of the RHEV manager used for discovery will be automatically displayed against the respective parameters.

If the RHEV hypervisor being monitored was not discovered via an RHEV manager, but you still want to use an RHEV manager for obtaining the outside view, then, you can select any IP address of your choice from the RHEL MGR host list. By default, this list will be populated with the IP addresses/host names of all the RHEV managers that were configured for the purpose of discovering the RHEV hypervisors. If you select an RHEL MGR host from this list, then the corresponding port number, domain name, and user credentials will be automatically displayed against the respective parameters.

On the other hand, if the RHEV manager that you want to use for metrics collection is not available in the RHEL MGR Host list, then, you can configure an RHEV manager on-the-fly by picking the Other option from the RHEL MGR Host list.  An ADD THE RHEV MANAGER DETAILS window will then pop up. Refer to Configuring an RHEV Manager to Use for Monitoring the RHEV Hypervisor to know how to add an RHEV manager using this window. Once the RHEV manager is added, its IP address, port number, domain name and user credentials will be displayed against the corresponding parameters.

Confirm Password

Confirm the RHEL MGR Password by retyping it here.

SSL

If the RHEV manager to which the eG agent should connect is SSL-enabled, then set this flag to Yes. If not, set it to No.

Ignore VMs Inside View

Administrators of some high security RHEV 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 RHEV 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 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 use the RESTful APIs on the RHEV Manager to Obtain the “Outside View” 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,
Admin User,
Admin Password,
Confirm Password

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:

  • If the VMs belong to a single domain:  If the guests belong to a specific domain, then specify the name of that domain against the Domain parameter. In this case, any administrative user in that domain will have remote access to all the virtual guests. Therefore, an administrator account in the given domain can be provided in the Admin User field and the corresponding password in the Admin Password field. Confirm the password by retyping it in the Confirm Password text box.
  • If the guests do not belong to any domain (as in the case of Linux guests):  In this case, specify "none" in the Domain field, and specify a local administrator account name in the Admin User below.

    Prior to this, you need to ensure that the same local administrator account is available or is explicitly created on each of the virtual machines to be monitored. Then, proceed to provide the password of the Admin User against Admin Password, and confirm the password by retyping it in the Confirm Password text box.

    If key-based authentication is implemented between the eG agent and the SSH daemon of a Linux guest, then, in the Admin User text box, enter the name of the user whose <USER_HOME_DIR> (on that Linux guest) contains a .ssh directory with the public key file named authorized_keys. The Admin Password in this case will be the passphrase of the public key; the default public key file that is bundled with the eG agent takes the password eginnovations. Specify this as the Admin Password if you are using the default private/public key pair that is bundled with the eG agent to implement key-based authentication. On the other hand, if you are generating a new public/private key pair for this purpose, then use the passphrase that you provide while generating the pair. For the detailed procedure on Implementing Key-based Authentication refer to Troubleshooting.

  • If the guests belong to different domains - In this case, you might want to provide multiple domain names. If this is done, then, to access the guests in every configured domain, the test should be configured with the required user privileges; this implies that along with multiple Domain names, multiple Admin User names and Admin Passwords would also have to be provided. To help administrators provide these user details quickly and easily, the eG administrative interface embeds a special configuration page.

    To access this page, simply click on the Click here hyperlink that appears just above the parameters of this test in the test configuration page. To know how to use the special page, refer to Uptime - VM Test.

  • If the Inside View Using flag is set to ‘eG VM Agent (Windows)’ - In this case, the inside view can be obtained without domain administrator privileges. Therefore, set the domain, admin user, and admin password parameters to none.

Report By User

While monitoring a RHEV Hypervisor, the Report By User flag is set to No by default, indicating that by default, the guest operating systems on the hypervisor are identified using the Hostname specified in the operating system. On the other hand, while monitoring a RHEV Hypervisor - VDI, this flag is set to Yes by default; this implies that in case of the VDI model, by default, the desktops will be identified using the login of the user who is accessing them. In other words, in VDI environments, this test will, by default, report measures for every username_on_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.

Detailed Diagnosis

To make diagnosis more efficient and accurate, the eG Enterprise 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

Has VM been rebooted

Indicates whether the VM has been rebooted during the last measurement period or not.

 

Boolean

If this measure shows 1, it means that the guest was rebooted during the last measurement period. By checking the time periods when this metric changes from 0 to 1, an administrator can determine the times when this guest was rebooted. 

Uptime of VM during the last measure period

Indicates the time period that the VM has been up since the last time this test ran.

Secs

If the guest has not been rebooted during the last measurement period and the agent has been running continuously, this value will be equal to the measurement period. If the guest was rebooted during the last measurement period, this value will be less than the measurement period of the test. For example, if the measurement period is 300 secs, and if the guest was rebooted 120 secs back, this metric will report a value of 120 seconds.  The accuracy of this metric is dependent on the measurement period - the smaller the measurement period, greater the accuracy.

Total uptime of the VM

Indicates the total time that the VM has been up since its last reboot.

Mins

Administrators may wish to be alerted if a guest has been running without a reboot for a very long period. Setting a threshold for this metric allows administrators to determine such conditions.

Note:

  • If a value less than a minute is configured as the Test Period of the Uptime - Guest test, then, the Uptime during the last measure period measure will report the value 0 for Linux VMs (only) until the minute boundary is crossed. For instance, if you configure the Uptime - Guest test to run every 10 seconds, then, for the first 5 test execution cyles (i.e., 10 x 5 = 50 seconds), the Uptime during the last measure period measure will report the value 0 for Linux VMs; however, the sixth time the test executes (i.e, when test execution touches the 1 minute boundary), this measure will report the value 60 seconds for the same VMs. Thereafter, every sixth measurement period will report 60 seconds as the uptime of the Linux VMs. This is because, Linux operating systems report uptime only in minutes and not in seconds. 
  • For VMs running Windows 8 (or above), the Uptime - VM test may sometimes report incorrect values. This is because of the 'Fast Startup' feature, which is enabled by default for Windows 8 (and above) operating systems. This feature ensures that the Windows operating system is NOT SHUTDOWN COMPLETELY, when the VM is shutdown. Instead, the operating system saves the image of the Windows kernel and loaded drivers to the file, C:\hiberfil.sys, upon shutdown. When the Windows VM is later started, the operating system simply loads hiberfil.sys into memory to resume operations, instead of performing a clean start. Because of this, the Windows system will not record this event as an actual 'reboot'. As a result, the Uptime - VM test will not be able to correctly report if any reboot happened recently ; neither will it be able to accurately compute the time since the last reboot.

    To avoid this, you need to disable the Fast Startup feature on VMs running Windows 8 (and above). The steps to achieve this are outlined below:

    1. Login to the target Windows VM.
    2. Edit the Windows Registry. Look for the following registry entry:

      HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Power

    3. Locate the HiberbootEnabled key under the entry mentioned above.
    4. Change the value of this key to 0 to turn off Fast Startup. By default, its value will be 1, as Fast Startup is enabled by default.

      Also, note that the Fast Startup feature does not work if the VM is “restarted”; it works only when the VM is shutdown and then started.