I am trying to write a backup solution, which will take snapshots of a folder using hardlinks and rsync, every hour it will run though its thing, and take the snapshot. I have most of it sorted already, it's just small details that I'm missing.
I'm already planning a system that will clear out old backups depending on how far apart they are, and how old they are in a sort of exponential backoff fashion. It will therefore not take up dramatically much disk space to keep hourly backups. (the age of each backup is divided by the backup one after it...)
I will however be running this on a machine that will regularly have no changes to backup (overnight, when people are on holiday, etc.) and as such, I'd like to take this into account. If only for the purposes of power saving.
Is there any way tell when the last modified time of the entire /home/ directory is?
Perferably without fully traversing the directory, as this would somewhat defeat the point.
Is there any better way to do this?