snapshot backups

Incremental backups (last hour, last day, last week, last month, etc.)
Only backs up changes each time, yet allows you to see a “snapshot” at each previous interval
Requires about 2x disk space with rsync/hard-link method
True snapshots require fancy filesystems (LVM, or commerical products)

Incremental backups (last hour, last day, last week, last month, etc.)