Suddenly openPDC Archive file name changed


Hi Stephen
Thank you for your all time help.My openPDC Archive was working fine with .d file naming.example: ppa_archive_2019_02_01 23!21!52.700 to 2019_02_01 00!40!35.633.d.Suddenly it has changed and archiving as ppa_archive.d and ppa_archive.standby.Please tell me how can I restore the previous file format.
Thank you.


Hi bapi,

The ppa_archive.d file is known as the “active” file in an openHistorian 1.0 archive. That means that this is the main file that the system is actively writing to, and all other archive files remain fairly static. If the other files did not remain static, the historian would have a hard time placing a timestamp in the name of the file because it would always be changing. Once the active file is full, it will be renamed with timestamps to become a historic file and a new file will be swapped in to become the active file. This process is called “rolling over”.

The ppa_archive.standby file is, unsurprisingly, known as the “standby” file. As the active file reaches the point where it is likely to rollover very soon, the standby file is created in preparation for the rollover. This allows the historian to preallocate disk space for the new active file so that the rollover can happen more quickly and will therefore likely be more reliable and require less downtime.

These files have always existed as part of the normal process for archiving data, and your archive should still be creating those timestamped historic files during the rollover process. You should just need to wait until your active file is full.



Hello Stephen
Thank you.The problem is solved.