Foglight Change Analyzer 5.6.16 - User and Reference Guide

The Change History view lists all changes that occurred to VMs, resource pools, hosts, clusters, disks, datastores, and data centers within a selected environment over a selected timeframe.

Description of view elements

This view is made up of the following elements:

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Change History—Selectors bar

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Change History—Quick view

Change History—Selectors bar

Table 6. Change History—Selectors bar

Description

This bar allows you to specify the objects for which you want to see the change history.

Data displayed

Filter Object. Allows you to select the VMs to be included in the report.

Environment selector. Allows you to select the environment to be analyzed. The following options are available by default in the drop-down list (additional user-created items may appear in the list as well):

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Object selector. Allows you to select the object to be analyzed.

Event Source Type. Allows you to select the type of events for which you want to see the change history. The following options are available in the drop-down list:

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FVE-initiated changes

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VMware

Search box. Allows you to type the name of a virtual object to be analyzed.

Where to go next

The Change History—Quick view is updated to display the change history for the selected objects.

Change History—Quick view

Table 7. Change History—Quick view

Description

This view displays the change history for the objects selected in the Change History—Selectors bar.

Data displayed

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Change Date. Shows the date and time of the change.

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Object Name. Shows the virtual object name.

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Change Type. Shows the type of change. For a list of change events being monitored and reported, see Table 3.

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Before. Shows the value of the configuration parameter before the change.

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After. Shows the value of the configuration parameter after the change.

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User Name. Shows the name of the user who made the change.

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Parent Object. Shows the parent object for the selected object.

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Revert Change. Click the Revert Change link to open the Implement a Change dialog box, which allows you to revert a change, provided that you have the proper credentials. This link is available only for select type of changes.

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Object Type. Shows the object type.

Where to go next

Drill down on: N/A

Impact Analysis view

To open the Impact Analysis view, click the Impact Analysis icon on the Change Analyzer tab > Menu bar.

For more details, see the following topics:

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Purpose

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Description of view elements

Purpose

The Impact Analysis view allows you to define a sequence of changes and see what impact those changes have on your system’s performance. It also allows you to trigger the execution of these changes immediately or schedule these changes within Foglight or Foglight for Virtualization, Enterprise Edition. For detailed information about how the performance impact is calculated, see Performance impact assessment.

Performance impact assessment

This section presents the algorithm used by Foglight Change Analyzer to calculate the performance impact of a modeled change on your system.

Calculate the total available cumulative CPU, Memory, Storage, and Throughput resources (Total Resource). Account for the warning threshold and failover resource requirement. For example, in a 4-host cluster where each host has 8GB of memory, the Memory Warning Threshold is set to 80%, and a single host is reserved for failover, the total available cumulative Memory resource would be 19.2GB (32GB - 8GB * .80).

Calculate the total required cumulative CPU, Memory, Storage, and Throughput resources prior to the change(s) (Current Requirement). This would be the sum of the actual average utilization or resource reservation, whichever is larger, for each powered-on VM currently deployed.

Calculate the total required cumulative CPU, Memory, Storage, and Throughput resources after the change(s) (Change Requirement).

If the Current Requirement is less than the Total Resource, and the Change Requirement is less than the Total Resource, there is no performance impact (for the resource) as a result of the change.

If the Current Requirement is less than the Total Resource, and the Change Requirement is greater than or equal to the Total Resource, performance will be degraded (for the resource) as a result of the change, due to a lack of resource equal to the absolute difference between the Change Requirement and the Total Resource.

If the Current Requirement is greater than or equal to the Total Resource, and the Change Requirement is less than the Total Resource, the current performance impact (for the resource) will be improved as a result of the change, due to a gain in resource equal to the absolute difference between the Current Requirement and the Total Resource.

If the Current Requirement is greater than the Total Resource, the Change Requirement is greater than the Total Resource, the absolute difference between the Current Requirement and the Change Requirement is greater than 5% of the Total Resource, and the Current Requirement is less than the Change Requirement, the current performance will be further degraded (for the resource) as a result of the change, due to a lack of resource equal to the absolute difference between the Current Requirement and the Change Requirement.

If the Current Requirement is greater than the Total Resource, the Change Requirement is greater than the Total Resource, the absolute difference between the Current Requirement and the Change Requirement is greater than 5% of the Total Resource, and the Current Requirement is greater than the Change Requirement, the current performance impact (for the resource) will be reduced but not eliminated as a result of the change, due to a gain of resource equal to the absolute difference between the Current Requirement and the Change Requirement.

In all other cases, there is no performance impact.