Troubleshooting
Problem
This document provides additional information regarding the Data Protection for SQL Differential backup versioning as managed on the Tivoli Storage Manager Server.
Cause
After a Full backup is done, all the previous backup versions are inactivated. This means there is NO active version of the Differential backup once a fresh Full Database Backup is performed.
Resolving The Problem
Data Protection for SQL inactivates all backup objects for an SQL database (not otherwise inactivated) whenever a new FULL database backup of that SQL database is performed. This inactivation of any prior Differential database backups will eliminate the ACTIVE version of the Differential backup. Thus, the version retention will utilize the values for the "Version Data Deleted" parameter within the Backup Copy Group.
Note that if there are multiple Differential backup versions (prior to performing the FULL), this would include an ACTIVE version of the Differential backup. Since there is an ACTIVE version of the backup, this causes the "Versions Data Exists" parameter to be used for the retention policy. It is only when no ACTIVE version of the Differential exists (such as would happen after a FULL backup), that the VerDeleted parameter is then utilized.
Example:
Version Data Exists: 10000
Version Data Deleted: 31
Retain Extra Vers: 31
Retain Only Vers: 31
Data Protection for SQL Backups will adhere to the "Version Data Exists" parameter and retain 1000 versions of the database. However, this VerExists parameter will only be honored until the next SQL FULL database backup is performed with the DP client. Once the FULL SQL DB backup is completed, the Differential backups will all be marked as INACTIVE and will honor the "Version Data Deleted" parameter, which will only keep 31 versions.
One recommendation for setting the retention is to:
• Set VERSIONS DATA EXISTS and VERSIONS DATA DELETED to NO LIMIT.
• Set RETAIN EXTRA VERSIONS and RETAIN ONLY VERSION to the desired amount of days that need to be kept in order to go back and restore from.
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Document Information
More support for:
Tivoli Storage Manager for Databases
Software version:
All Versions
Operating system(s):
Windows
Document number:
342509
Modified date:
17 June 2018
UID
swg21216262