3 Replies Latest reply on Aug 30, 2018 12:44 PM by VasanthakumarR

    Does turning archiving off save space in archive files?


      My understanding of archives is thus:

      1. When an archive shift occurs, a new primary record is added to the new primary archive for every tag on the system. This then fills with data.
      2. When a tag's primary record is full, an overflow record is created for further data for that tag.
      3. When the archive is 'almost full' of primary and overflow records, an archive shift takes place and we return to step 1.

      My question is, does step 1 also apply for tags whose Archiving attribute is set to False?

      The reason I ask is that we need to collect data for a large number of tags (around 1.2 million) but only for a limited time span. Once we have finished collecting this data, any new primary records for these tags would be empty (the interface will not even be running) and just use up space in the archive. We could delete the tags once we have finished but then we will also lose access to the historical data we have collected.

        • Re: Does turning archiving off save space in archive files?

          Hi Alistair,


          If your archiving attribute is set to "0" for a given tag, a primary record will still be initialized in the archive during an archive shift.  Generally, a primary record is always initialized for every point created on the server regardless of the tag configuration.  However, obviously when the archiving attribute is set to "0" == "OFF", then no incoming data will be archived while this is the case, however, the primary record is still initialized so that if archiving is re-enabled, the archives will be ready to store data for the point.


          The answer to your question, Whenever the Archive shift happens primary record will get initialized for all the points if you turn Archiving off in the tag configuration. Hence archiving off will not save your archive space. I recommend you to increase the hard drive space to accommodate more data.




          3 of 4 people found this helpful
            • Re: Does turning archiving off save space in archive files?

              Oh, ok, that's a shame, I would have thought it would be quite easy to only add a primary record whenever a tag's Archiving was set to on but I can understand that might require changes to the data retrieval as well. It's just slightly annoying that we have to use up around 1GB in every archive going forward in order to maintain access to a couple of months of historical data. In our current scenario, the data is not that important so can be lost after the initial collection and analysis but I can imagine scenarios where this behaviour would be a problem.


              However, My original question has been answered, so thank you for the quick and informative response.