tape retention in days specifies the number of days that must elapse between the creation of a tape file and the time at which you can overwrite it with another dump. This server-wide option, which you can set with sp_configure, applies to all dumps requested from a single Adaptive Server.
Use the retaindays = number_days option to override the tape retention in days parameter for a single database or transaction log dump. The number of days must be a positive integer, or zero if the tape can be overwritten immediately.
tape
retention in days and retaindays are
meaningful only for disk, 1/4-inch cartridge, and single-file
media. On multifile media, Backup Server checks only the expiration
date of the first file.
