PI Backup will not backup empty archives (makes no sense to backup them as they do not contain any data). For an empty archive the Start and End Time are both "Current Time".
For your primary archive the Start Time will not be empty, however the End Time will be "Current Time". Typically, the primary archive is always included in the PI backup. What do you have in column "Backup Time" in SMT -> Operation - Archives Backup Time ? Is your PI Data Archive Server running? Is the PI Archive Subsystem service running?
thanks for quick response
- Archives backup time = Never
- PI Backup Subsystem = Running
Can you please provide some more details on what you have done to perform the backup and on how you assess that the primary archive file has not been backed up?
As the problem occurs in a specific scenario I ask you to submit this information to Technical Support, so we will open a support case and further support you and resolve the problem.
We will probably need to have a remote session to better understand your scenario and to explain why the primary archive was not backed up.
In general, the following KB Article is a good resource to get familiar with best practices on PI Data Archive Backup: KB01032 - PI Data Archive Backup Best Practices
In addition to what Gerhard mentioned regarding the primary archive, could you also provide the command line you used to run the backup? Also what version of PI Data Archive are you using? To see the current status of a backup (or status of previous backup), can you provide the output of "piartool -backup -query"?
You can also view all PI Backup history and what files were included/not included and for what reason in PI SMT -> Operation -> Backups for more information.
Another thing to mention, running a backup using piartool is good for "on-demand" backups, but make sure you have also configured the PI Backup scheduled task which will backup the PI Data Archive at 3:15am each night (default).