Personal IT: Automated backup for the home office
Two things are important when it comes to backups:
- Backup copies for protection against short-term loss (e.g. hard disk fail).
- Archived copies for protection against long-term loss (e.g. deletion, catastrophy).
I run the following backup procedure to protect the home office:
- Everyday: Copy all important files to a separate physical hard disk used purely for backups. For protection against complete machine failure, preferably this is in a separate machine to those storing most of the data that gets backed up.
- 1st Mon of month: Burn all data to a permanent DVD+R archive that is stored off site.
- 2nd Mon of month: Reburn all data to the Mon2 DVD+RW.
- 3rd Mon of month: Reburn all data to the Mon3 DVD+RW.
- 4th Mon of month: Reburn all data to the Mon4 DVD+RW.
- 5th Mon of month: Reburn all data to the Mon5 DVD+RW.
- Every Wed: Reburn all data to the Wed DVD+RW.
- Every Fri: Reburn all data to the Fri DVD+RW.
This system requires a hard disk, 6 DVD+RW’s and one DVD+R each month. It provides the following levels of protection:
- Daily copy of all files to separate hard disk.
- 3 snapshot points during the latest 7 days.
- One snapshot point per week for the last month.
- One snapshot point per month indefinitely.
The maximum possible loss scenarios are:
- If you lose a single data hard disk then you should lose no more than one day’s work.
- If you lose the backup hard disk and a data hard disk simultaneously, there will be no more than 2 days work lost.
- If you lose the entire office, there will be no more than 1 months work lost. As the office size grows, you can protect your data more rigorously by increasing the frequency of the archival points. For example, reburn data DVD’s on Tue and Thu as well while making an archive copy every Monday rather than every 1st Monday. Similarly if your data set grows beyond a single DVD (4.7GB), simply add a second DVD burner and effectively double your capacity by using A & B disks on each day.