Data Migration Scenarios

You can migrate tags and their data on the same Historian Server or between servers. When migrating your data, consider the following guidelines:

• Get new collection working first

  When the data is collected from the collectors or the API programs, then you should consider adding the tag definitions into the destination server and directing data to be written there before you start migration, because migration may take several hours or days.

• Migrate data from oldest to newest

  It is advisable to migrate the oldest data first and then the newest, to make the optimal use of archive space.

• Pay attention to TagID

  Every tag in Historian 4.5 and above has a property called TagID, that uniquely identifies it and allows data retrieval to locate the data. Even if you have a tag of with the same name in another archiver, that tag has a different TagID and is considered as a different tag. You can see the TagID of a tag in the Excel Tag Export. Preserve that number when moving a tag from one system to another.

The following are commonly used scenarios while migrating data on the same Historian server or between servers.

• Migrating a Tag and its data from one data store into another data store.
• Merging a Historian Server into an existing data store on another machine. See Merging a Historian Server.