Archive De-fragmentation - An Overview

What is De-fragmentation? Having an IHA file with contiguous data values for a particular tag is called Archive De-fragmentation.

An Historian IHA (Historian Data Archive) file could contain data values for multiple tags and data written for a particular tag may not be in continuous blocks. This means data values in IHA files are fragmented.

Archive De-fragmentation improves the performance of reading and processing of archive data dramatically.

De-fragmentation of existing archives:
  • An archive can be de-fragmented, when it is not active.
  • A command line based tool can be used to run on any existing archive as needed.
  • De-fragmentation can be done on all versions of archives, and the resulting archive will be the latest version.
  • The de-fragmentation must be started manually.