2. Enter the following information on the General tab: 

Name: Enter a descriptive name for the union. This is the archive name that will be visible to the clients.

Description: Enter a more precise description of the union in this field.

Index Folder: Enter the path to the index folder where the union should be stored. Do not use an existing index; create a new index folder for the union index. Later, you will add members to the union, i.e., existing indexes that will be joined together or configured with backup solutions. 

Update interval: Choose how often (in seconds) the union should check the connected union members to look for updates:

• Decrease the interval at which members are checked for updates. This is useful if union members are frequently updated and you want to ensure the archive is fully up to date. It will, however, increase network and processor load on the union server. If you need to decrease the interval but find the union server is slowing down, try reducing the browse size for each union member.
• Increase the interval if the members should be checked for updates less frequently. This is useful for indexes that rarely change, or when the processor or network load is too high. You can also try decreasing the browse size for each union member to reduce processor load.

A search always returns the newest files and is unaffected by this setting. It only applies to browsing the archive. The number of seconds between updates can range from 1 to 1,000.

Indexing options: Enable or disable the union by selecting an option. If you are configuring a union that combines several indexes, you can also choose whether you will allow partial search results if one of the attached indexes fails to respond. This may, of course, return an incomplete search result, but it might be a better option than letting the search fail altogether.

Member indexes

On the Member indexes page, you can add indexes to the union. To combine several indexes in a large archive, add primary members to the union. Select + below the list of indexes to add new indexes to the union.

By default, the connection window that opens lists indexes on the local server. However, you can easily connect to indexes on another server by entering that server's hostname. You may have to authenticate the first time you connect to a remote server. The access credentials are then stored in the local Operations Center Settings (under Server Settings | Authentication) for future use.

What's next?

Now, you can save the union or define an access list for it. For more information, see Setting access permissions on a union.