In the first part[1] of this three-part series using a Raspberry Pi for network-attached storage (NAS), we covered the fundamentals of the NAS setup, attached two 1TB hard drives (one for data and one for backups), and mounted the data drive on a remote device via the network filesystem (NFS). In part two, we will look at automating backups. Automated backups allow you to continually secure your data and recover from a hardware defect or accidental file removal.
Backup strategy
Let's get started by coming up with with a backup strategy for our small NAS. I recommend creating daily backups of your data and scheduling them for a time they won't interfere with other NAS activities, including when you need to access or store your files. For example, you could trigger the backup activities each day at 2am.
You also need to decide how long you'll keep each backup, since you would quickly run out of storage if you kept each daily backup indefinitely. Keeping your daily backups for one week allows you to travel back into your recent history if you realize something went wrong over the previous seven days. But what if you need something from further in the past? Keeping each Monday backup for a month and one monthly backup for a longer period of time should be sufficient. Let's keep the monthly backups for a year and one backup every year for long-distance time travels, e.g., for the last five years.
This results in a bunch of backups on your backup drive over a five-year period:
- 7 daily backups
- 4 (approx.) weekly backups
- 12 monthly backups
- 5 annual backups
You may recall that your backup drive and