Solution sheet

Compression While Active

Wasted space due to excessive deleted records is a vexing problem for some production IBM i shops due to the high uptime requirements of the applications and the long and unpredictable outage requirements for dedicated compression operations (RGZPFM). Compression While Active is a solution made possible through the combination of Assure MIMIX Promoter Copy Active File Technology and Precisely Global Professional Services. The ideal result of the solution is to enable customers to identify and minimize wasted space on IBM i production servers with minimal downtime.

Precisely offers a solution where a viable plan can be developed, tested and executed to compress files and recovery space while managing risk and downtime.


  • Compressions performed with near-zero downtime
  • Leverage of the experience and expertise of Assure MIMIX specialists
  • Activities can be performed during normal business hours without burdening IT teams or business operations
  • Comprehensive planning and testing to ensure a viable process

How Compression While Active Works

There are a number of ways to compress IBM i files with deleted records including:

  • Shuffling active records to the top of a replicated file and removing the deleted records from the replicated file.
  • Copying the active records of a PROD file to a TEMP file and switching the TEMP file to production at a convenient time.
  • Compressing deleted records in a replicated environment and syncing the changes back to the production library.

No matter what process you choose to compress deleted records, Assure MIMIX replays the process in a replicated environment. For libraries with significantly large files, you can pause the replication process to compress the file on the production systems before restarting to replicate the now-compressed file to the target system.

You can also perform the compression and replication process from the backup target system, neatly fitting the role swap promoting the compressed file to the production system during a predetermined maintenance window.

Compression While Active Solution Sheet