There are a number of useful concepts to consider when you manage data collection devices for off-box log storage. This reference material might prove helpful in setting up and maintaining your data collection device (DCD) configuration.

1. At the top of the screen, click System.
2. On the left, expand BIG-IQ DATA COLLECTION and then select BIG-IQ Data Collection Devices.
   The BIG-IQ Data Collection Devices screen opens to display the currently defined data collection device cluster.
3. Click the Settings button.
   The Settings screen opens to display the current state of the DCD cluster defined for this BIG-IQ device.
4. You have two options for choosing a snapshot and starting the restore, using the settings in the External Storage & Snapshot area near the bottom of the screen.

   Option	Description
   To restore from the most recent snapshot:	Next to Last Snapshot/Time, click Restore Latest.
   To select the snapshot that you want to restore:	Click the View History button. Choose the snapshot you wish to restore, and click Restore.

1. At the top of the screen, click System.
2. On the left, expand BIG-IQ DATA COLLECTION and then select BIG-IQ Data Collection Devices.
   The BIG-IQ Data Collection Devices screen opens to display the currently defined data collection device cluster.
3. Click the Settings button.
   The Settings screen opens to display the current state of the DCD cluster defined for this BIG-IQ device.
4. Near the bottom of the screen, click the View History button.
   The BIG-IQ Data Collection Snapshots screen opens.
5. Browse through the list to find the snapshot you want to delete.
6. Select the check box for the snapshot you want to delete, and click Delete.

1. At the top of the screen, click System.
2. On the left, expand BIG-IQ DATA COLLECTION and then select BIG-IQ Data Collection Devices.
   The BIG-IQ Data Collection Devices screen opens to display the currently defined data collection device cluster.
3. Click the Settings button.
   The Settings screen opens to display the current state of the DCD cluster defined for this BIG-IQ device.
4. Inspect the DCD cluster details listed in the Summary area.

   Data Cluster Status

   Look here for information about the current state of the cluster.

   Master Device

   The read-only Master Device field displays the host name of the BIG-IQ device that manages and monitors the health of this DCD cluster.

   Devices in Cluster

   Displays the total number of devices in the cluster including DCDs, the BIG-IQ Centralized Management devices and the optional peer.

   Data Collection Devices in Cluster

   Displays the number of DCDs that have been added to the cluster.

   Total Document Count

   Displays the number of all document types stored on the cluster. Alerts and events are included in this list, but the total includes other types of document as well.

   Total Document Size

   Displays the amount of disk space consumed by the documents stored for this cluster.

   This information provides a fairly detailed overview that describes the DCD cluster you have created to store data. After you complete an upgrade, you can check the health to verify that the cluster restored successfully.

The optimum settings used to configure your data collection device (DCD) indices depend on a number of key factors.

• The system provides the ability to dynamically create new indices based on either a specified interval or a specified size. The primary goal to consider when you make these decisions is how to maintain a maximum disk allocation for the DCD data, while maintaining capacity for new data that flows in.
• Secondary considerations include search optimization, and the ability to optimize old indices to reduce their size.
• Generally, the best policy is one that does not create unnecessary indices. The more indices, the lower the overall performance, because your searches have to deal with more shards. For example, if a module knows that it has a low indexing volume (thousands/day) then it makes the most sense to have a large aggregation per rotation (5 days or 30 days). For components like Web Application Security that probably have high indexing volumes, it makes more sense to rotate every 8 hours (which reduces the number of retained indices).
• Index rotation also allows changing sharding and replica counts by changing the template on a given index type. New indices created from that template will contain the new shard and replica count properties.

This table shows the default configuration values for each index running on BIG-IQ^® Centralized Management. These values are based on anticipated data ingestion rates and typical usage patterns.

If multiple modules are running on a given DCD or if you have higher inbound data rates, you might have to adjust these values to keep the /var file system from filling up. (There is a default alert to warn of this when the file system becomes 80% full.)

The simplest resolution is to revise the retained index count; lowering this value reduces the disk space requirements, but it will also reduce the amount of data available for queries. For details on changing this setting, refer to the modifying indices topic for the component you are configuring.