Server backup is your last line of defense against data loss. Hardware failure, cyber attacks, human error, or natural disasters can all cause data loss.
3-2-1 Backup Rule
3 copies: At least 3 copies of your data.
2 different media: Store on 2 different storage types.
1 offsite: At least 1 backup at a different location.
Backup Types
Type
Description
Pro
Con
Full
Complete copy
Fast restore
Slow, large size
Incremental
Changes since last backup
Fast, small
Restore chain needed
Differential
Changes since last full
Middle ground
Grows over time
Linux Backup Tools
rsync: Efficient file synchronization over SSH.
tar + cron: Automated compressed archives.
mysqldump: MySQL/MariaDB database backup.
Restic / Borg: Modern encrypted incremental backup with deduplication.