EZ-Backup's Retention of Multiple File Versions
This article applies to: EZ-Backup
How many versions and for how long are files kept/saved with EZ-Backup? For example, can I specify the number of versions of each file to keep or is it time based (keep all versions less than 30 days old)? What are the limits for this feature?
There is quite a bit of flexibility here.
An EZ-Backup "management class" defines things such as how many extra versions of a file are kept, and for how long. This can be specified separately for files that exist on your workstation vs. files that have been deleted from your workstation. Files on a workstation can be mapped to different management classes, allowing you to have different levels of backup (or archive) protection for different types of files. This mapping is done using rules that are placed into the EZ-Backup options file (TSM Backup Preferences or dsm.opt) on the workstation. The rules can have wildcards in them, making it easier to map classes or collections of files with one rule. If you don't map a file to a management class, it is mapped to a default management class.
For backed up data (vs. archived data), the defaults are:
If file exists on workstation:
Number of backup versions to keep: up to 3
Number of days to retain extra versions: up to 30
If file no longer exists on workstation:
Number of backup versions to keep: 1
Number of days to retain last version: 60
For archived data:
When a file is archived, by default, it does not expire. However, at the time a file is archived, a management class may be selected which designates a retention period for that file. For files that have a retention period of more than six months, we keep a mirror copy of that file. If the file is deleted from the workstation, the archive data will remain for the duration of the retention period associated with that file.
IBM has produced a Technote on this topic.
For departments with quite a few computers, we can set up a departmental "Policy Domain" which has its own private set of "management classes". It is strongly suggested that departments have their own policy domain if they have several computers. This way we can tailor management classes to your department's special requirements.
The list of management classes, and their definitions, can be viewed from the EZ-Backup software program running on your workstation (see Viewing Policy Information). To get a new management class set up, simply tell us what you need and we will set it up for you. Once set up, you can use it however you wish by specifying appropriate rules in the EZ-Backup client options file.
For more in-depth information on management classes, refer to the TSM/ADSM manuals for your platform.