Using Snapshots to Monitor Devices

CloudVision enables you to monitor changes in the state of the devices in your network over time through the use of snapshots.

Note: Starting from 2018.2.0 release, snapshots UI is available as part of the Device View in Telemetry.

Sections in this chapter include:

About Snapshots

In CloudVision, the snapshot service runs as a scheduler to capture device snapshots periodically.

The information recorded in snapshots provides you with insights on the configuration, EOS image, and other aspects of the device. Snapshots are captured for individual devices (single switches) only.

Standard Information in Snapshots

The information recorded in the snapshot reflects the state of the device at the time snapshot was captured. A snapshot only contains outputs of custom commands that are part of a snapshot template. (You must select a snapshot template when you capture a snapshot.) See Defining Custom Snapshot Templates andEditing Custom Snapshot Templates for information on using snapshot templates.

When upgrading to the 2018.2 train, only snapshot templates are migrated but not previous snapshots. CloudVision stores migrated templates without any device list associated with them. Hence, they are marked as unscheduled. However, these templates can be used to capture snapshots before and after change controls.

How to Use Snapshots

In CloudVision, snapshot service schedules and periodically captures the outputs of commands that are specified in the template. The frequency of capturing command outputs is based on the scheduling frequency mentioned in the snapshot template. The information recorded in snapshots can provide you with insights on the configuration, EOS image, and other aspects of the device. Snapshots are captured for individual devices (single switches) only.

The main uses of snapshots are:

  • Viewing snapshots to understand the state of a device at a given time, or over time.

  • Comparing snapshots to see the change in state of a device between two points in time.

  • Comparing snapshots to see the state of a device before and after a change control.

Accessing Snapshots

Snapshots are stored under the CVP dataset, which you can access any time for detailed analysis. The Snapshots page displays all valid snapshots created over time. Each valid snapshot provides the following additional information:

  • Name - The name of the template (you assign the name when you create the template).

  • Capture Time - The date and time when the snapshot was last captured.

  • Last Executed By - The user that captured the snapshot.

It also allows navigating to snapshots of the corresponding snapshot template.

Figure 1. Snapshots Page

You can navigate to the Snapshots page through one of the following paths:

  • Inventory > Device_ID > Snapshots

  • Network Provisioning > Right-click on the required device > Snapshot.

Accessing Snapshot Configurations

The Snapshot Configuration page displays all snapshot templates created over time. It further allows you to edit current snapshot configuration, navigate to the Snapshots page, view the status of each snapshot configuration, and create a new custom snapshot configuration.

Figure 2. Snapshot Configuration Page

You can navigate to the Snapshot Configuration page through one of the following paths:

  • Inventory > Device_ID > Snapshots > Snapshot Configuration

  • Network Provisioning > Right-click on the required device > Snapshot > Snapshot Configuration.

Defining Custom Snapshot Templates

To ensure that snapshots contain the information you need for effectively monitoring changes in the state of devices over a certain period of time, CloudVision allows you to define custom snapshot templates.

A snapshot template defines commands, outputs of which need to be captured as part of the snapshot using that template. When you create a snapshot template, associate a list of devices, and set an execution frequency with it, the snapshot service starts capturing and storing snapshots for that template based on the scheduled frequency.

Complete the following steps to define a new custom snapshot template:

  1. Navigate to Inventory > Device_ID > Snapshots > Snapshot Configuration.
    The Snapshot Configuration page displays currently available snapshot templates.
  2. Click the (or create a new configuration) hyperlink at the lower right side of the page.
    The Snapshot Configuration page displays the Add Snapshot Configuration section.
    Figure 3. Add Snapshot Configuration Section
  3. In the Name field, type the name of the custom snapshot template.
  4. In the Commands field, enter the EOS CLI commands to be executed by the snapshot.
  5. If necessary, click the Devices drop-down and select required devices.
  6. Under Interval, Specify the frequency for capturing snapshots in either minutes, hours, or days.
  7. Click Save.
    The Snapshot Configuration page immediately displays the latest configuration along with the list of current configurations.
    Note: A snapshot configuration that is created without a device is saved and marked as unscheduled. Snapshot templates with bash commands are marked as invalid. However, these unscheduled and invalid templates can still be selected while creating a Change Control to capture pre and post change control snapshots.

Editing Custom Snapshot Templates

 

Complete the following steps to go to defined templates:
  1. Navigate to Inventory > Device_ID > Snapshots > Snapshot Configuration.
    The Snapshot Configuration page displays currently available snapshot templates.
  2. Click the snapshot name for editing the corresponding snapshot template..
    Figure 4. Edit Snapshot Configuration Section
  3. Modify the required information in corresponding fields.
  4. Click Save.

Viewing Snapshots Differences

You can take snapshots of single devices only. The exact set of information and presentation of the information in the snapshot is determined by the snapshot template you choose when capturing the snapshot.

Complete the following steps to view snapshots of a device:

  1. Go to the Network Provisioning page.
  2. Locate the device for which you want to view snapshots.
  3. Right-click on the device icon, then click Snapshot.
    Figure 5. Initiate Viewing Snapshot
    The All Snapshots page displays all valid snapshots.
    Note:

    You can also navigate to the All Snapshots page through Telemetry > Devices > Device_ID > Snapshots.

  4. Click on the snapshot template name for viewing the corresponding snapshot.
    Figure 6. All Snapshots Page
  5. Click the date and time breadcrumb for viewing all snapshots of the corresponding template.
    Figure 7. View All Snapshots
  6. Click the required snapshot to view the corresponding output.
    Figure 8. Select Snapshot
  7. Click Compare against a previous time for viewing corresponding snapshot differences.
  8. The page displays corresponding snapshot differences.
    Figure 9. Compare Snapshots
    Note:Snapshot differences are displayed in color codes to quickly identify significant changes in the state of the device over time. Click the Split tab for viewing snapshot differences in different windows.