Hi, I'm using Backup Exec 2016, there is a file server with 3TBs of data that should be backed up in a 4-week period of time, I created a Full-Incremental backup job and set “Keep for” option to 4 weeks for Full and 2-week for Incremental sets, now imagine if something happened and I loss all the data on file server in day 30. First I restore Full backup and all data will back to my file server as it was on first day of period (day 1), then Incremental backups should restore, logically refer to 2-week “keep for” time for Incremental sets, files in its database should belong to this period of time and all older sets overwrites by these 2-week-old new sets and there will be no set regard to first two weeks, and there will be a 2 week gap in redtored data, is it right and I should keep both my Full and Incremental sets for 4 weeks?
Since Backup Exec 2012 we have made sure that incremental backup sets (on disk) are chained together all of the way back to and including the full backup set that forms the complete chain for that sequence of backups - as such your first incremental will not be eligible for expiration and a reclaim(deletion) until the last incremental in the same chain can also be reclaimed. Addtionally if the chain is the most recent chain for a particular set of data we also default to blocking the reclaim of the chain even if the expiry date is reached (this default ability can be disabled)
Also note that you no longer have to restore the full and then each incremental in time order to get back to the latest state, Backup Exec builds restore slecetion lists to show a point in time view of the whole server based on the time of the incremental set you are looking at and if you select files for restore that are from an earlier parts of the chain and start a restore, as long as the media containing the chain are all online, Backup Exec mounts each part of the incremental chain as needed during the operation of the single restore job.
Note: we do no recommend an incremental forever strategy (an infinitely long incremental chain) and you should still run a periodic full backup to start a new chain.
Versions of Backup Exec prior to 2012 did not have the point in time view and would also allow backup sets on disk in an incremental chain to be overwritten early. Note for all versions of Backup Exec, backup sets on tape within an incremental chain could in thoery still be overwitten early - BUT the expection is that such tapes do not remain online and you cannot overwrite a tape that is offline.