Merge multiple archives into a single archive

To combine several archives, invoke the offline archive utility (piarchss) once for each input file, using the same output file for all the input files. Start from the oldest input file and continue in ascending time order (the offline archive utility will not work in descending or random time order). For example:

piarchss -if D:\pi\dat\oldest.arc -of D:\pi\dat\bigfile.arc
piarchss -if D:\pi\dat\newer.arc -of D:\pi\dat\bigfile.arc
piarchss -if D:\pi\dat\newest.arc -of D:\pi\dat\bigfile.arc

In this example, bigfile.arc does not exist prior to the operation. The first session creates the file and the second and third sessions add events to the file. By default, the utility creates the file as a dynamic archive. After you create the file, you can register the archive and PI Snapshot Subsystem can add events to the archive file.

Any of the three input files that were registered prior to the operation are unregistered during the operation. When the operation is complete, you can register them again. Dynamic archives, which are the default type created by the offline utility, are not shiftable.

You can move the output file's end time forward as required, but you cannot change the start time after creation.

Archives with an unknown end time should be processed into a new archive to determine the actual end time. The resulting archive can then be merged chronologically. Merging a series of archives with overlapping dates requires processing the archive with the oldest start time first, then process the remaining in chronological order based on the archive end times.

For more information about using the piarchss utility, see Offline archive utility command-line options and Run the offline archive utility.