As was stated in the previous answer, I had provided an explanation of the Archiving function, in that it was installed in a separate node as part of the 800xA system. With the move to History 6.0 which is included with all versions of 800xA 6.0 & 6.1, the 800xA History feature is now installed as part of the SCC tool, and as such, will contain PPA software during the installation. This will include the installation of the Archive Node, still as an independent node. There is a section of the 800xA History Administration & Configuration User Manual, (2PAA107563-600 B), that explains the steps required for the set up of Archiving.
Concerning the length of time that data can be stored in the History Server, my belief is that the tables in the manual are not complete for all configurations, and that the History Server can actually be utilized to store data for up to 10 years. It should be noted that the best way to determine the requirements for increased storage of data is to utilize the size estimation spread sheet provided in the ABB Library.
Although this sheet indicates that it is for History 2.0, my belief is that the formulas for determining space requirements on the History Server have not changed with History 6.0, and that this spread sheet can be utilized for both.