Using Drush for a Seven Day Daily Backup scheme for Drupal sites
Everyone needs to have a backup plan for their live site. Not only can your server's disk get corrupted, but you can also erroneously overwrite your site with bad code or bad data, or your site can get hacked. Detecting the latter situations takes some time. Hours or days.
For this reason, you should have multiple backup copies at multiple time points.
The most convenient scheme is to have a 7 day sliding backup: that is, you have one backup snapshot for each day of the week, with today's backup overwriting the backup from 8 days ago.