R2000i2 config.pro option documentation for: REGEN_BACKUP_USING_DISK            

regen_backup_using_disk

yes, no

specifies whether or not the system backs up the current model to disk before each regeneration. (you can change this setting at run time: choose utilities> environment, and select or clear make regen backupunder default actions in the environment dialog box.)

yesobacks up the current models to disk before every regeneration.

noodisables the backups.