I'm thinking about making my own archive/backup solution. This sounds like a bad idea, but I can't see another way to meet my requirements.
I have three Windows PCs I'd like to backup. They contain my work data and family pictures. Total is about 2 TiB and increasing. I'm worried about direct data loss (disk drives crashing), but also about data corruption (ransomware).
I was thinking to make a linux server with a btrfs partition. Every week, I'd copy all data to a new directory, and then run an offline btrfs deduplication action to conserve disk space. The layout would then look like
backup_pictures
20170601
file1.jpg
file2.jpg
20170608
file1.jpg
file2.jpg
file3.jpg
Dedup can figure out that file1.jpg and file2.jpg are the same, so they don't take up more disk space. The btrfs partition is only visible for linux; there would be another drive that's shared with the Windows PCs that can take in the new backup sets.
This would give me a fairly low-cost (below $500) solution with a lot of space and infinite retention time. Online service start at $40/month for this. I could even use btrfs sync to sync all files to another server, in a different physical location.
What am I missing?
