Proxmox storage
Lokaler Storage
Externer Storage
Backup Retention
The backup frequency and retention of old backups may depend on how often data changes, and how important an older state may be, in a specific work load. When backups act as a company’s document archive, there may also be legal requirements for how long backups must be kept.
For this example, we assume that you are doing daily backups, have a retention period of 10 years, and the period between backups stored gradually grows.
keep-last=3 - even if only daily backups are taken, an admin may want to create an extra one just before or after a big upgrade. Setting keep-last ensures this.
keep-hourly is not set - for daily backups this is not relevant. You cover extra manual backups already, with keep-last.
keep-daily=13 - together with keep-last, which covers at least one day, this ensures that you have at least two weeks of backups.
keep-weekly=8 - ensures that you have at least two full months of weekly backups.
keep-monthly=11 - together with the previous keep settings, this ensures that you have at least a year of monthly backups.
keep-yearly=9 - this is for the long term archive. As you covered the current year with the previous options, you would set this to nine for the remaining ones, giving you a total of at least 10 years of coverage.