Server Backup Policy


ACU uses Tivoli Storage Manager (TSM) for enterprise server backups. It is comprised of a TSM server that communicates with an agent that is installed on servers to perform backups. TSM utilizes an incremental-forever methodology once the initial backup is completed. It initially performs a full backup and then every subsequent backup is an incremental backup. If required, a full backup can be performed.

The TSM server manages what a full backup would look like at any given point in time via the concept of Active Files and Inactive Files. An Active File is one that still resides on the client that has been backed-up. An Inactive File is one that has been deleted from the TSM client but has a data retention policy requiring it to be maintained for a given amount of time.

The TSM data retention policies are configured with two types of parameters, versions and days, each of which identifies the retention for Active Files and Inactive Files. The Versions parameters are Versions Data Exists and Versions Data Deleted. Versions Data Exists pertains to Active Files and Versions Data Deleted pertains to Inactive Files. The Days parameters are Retain Extra Versions and Retain Only Version. Retain Extra Versions pertains to Active Files and Retain Only Version pertains to Inactive Files. The Versions Data Exists and Retain Extra Versions work together to retain Active Files. The Versions Data Deleted and Retain Only Version work together to maintain Inactive Files.

Settings for ACU Backups
The ACU production server’s Versions Data Exists is 30 versions for Active Files. Versions Data Deleted is also 30 versions. Versions Data Deleted is 30 days and Retain Only Version is 365 days. So, what does this all mean? For Active Files it means that up to 30 versions of a file will be retained for up to 90 days. If the 31st version of a file is backed-up prior to the 90 days, then the oldest version will drop off. If a file is backed up 12 times in the first 90 days, once the oldest file reaches 90 days old it will drop off. From that point forward each file will be removed from the system once it becomes 90 days old if no other backups of that file are made, until there is only one backup left and it will be retained for 90 days. Inactive Files follow the same methodology just using 30 and 365 respectfully.

Remote and Offsite Backups
The TSM server and tape library are on a separate floor from the servers. A set of tapes are created for off-site storage.  Each day tapes are transported to an off-site storage location and tapes that have expired are retrieved from off-site storage to be returned to the scratch tape designation. This process takes place every business day. The off-site rotation of Banner and Creative Services data is done once per week on Fridays. If Friday falls on a holiday, the rotation is done the previous workday.

Document Information
Created: James W Brents Jr, January 29, 2010
Last Updated: Gerald Coleman, Oct, 31, 2012
Submitted To: CIO Cabinet