Backup

tar — archiving and extracting files

Packs files into a compressed archive; an archive with no top directory dumps its files into the current directory.

PostgreSQL — access, pg_hba.conf, dump and restore

PostgreSQL is a relational DBMS: roles and databases, pg_hba.conf access rules, pg_dump dumps and pg_restore restores.

rsync — file synchronization and copying

Copies only the differences between trees; --delete mirrors the source into the destination, removing anything extra.

restic — deduplicated backups

Incremental encrypted backups with snapshots; without the password the repository cannot be decrypted at all.