You definitely should take a look at the Save-While-Active backup feature of OS/400. I have used BRMS/400 to implement a Save-While-Active strategy on our 1.5TB system and love it.
"Save While Active" enables objects to be saved while they are being used. The system ensures the entire object saved to the save media is consistent with the status of the object when the save operation was started. It really works, too. I have done many Disaster Restore Tests with my Save-While-Active backup media and the recoveries have all worked flawlessly.
Refer to the Backup and Recovery book, SC41-5304, for an overview of this functionality.
I would recommend, from a usability point of view, that you quiesce the system for a few minutes in order to obtain a synchronization point. It may still take several hours to copy data to tape, but the system may be used while the backup is running.
On my system using SWA results in the application being unavailable to my users for only about 15-20 minutes whenever I run a backup.
Some things to consider when using SWA...
1. SWA is a wonderful tool. It is a bit complicated to configure but well worth the trouble.
2. You could configure your backup process to eliminate ALL downtime, but in my opinion. It isn't worth the effort.
3. Quiesce your system for a short time instead, in order to obtain a synchronization point.
4. In the event of a recovery, you will be able to recover data to the time of this synchronization point.
5. You cannot use SWA for SAVSYS. To execute a SAVSYS command still requires that the system be in a restrictive state.
6. As with any backup, run it during a time of light system use.
7. Because of the extra processing required for SWA processing your backup will run longer, but users can use the system while it is running.
This feature should allow you to change your backup downtime window from 2.5 hours to less than 30 minutes! Give it a try.
================================== MORE INFORMATION ON THIS TOPIC ==================================
Ask the Experts yourself: Our backup & recovery gurus are waiting to answer your questions.
Search400.com's targeted search engine: Get relevant information on backup & recovery.
Check out this Search400.com Featured Topic on backup & recovery.
This was first published in April 2004