I’ve run multi-tiered disk-to-disk and disk-to-tape backup systems, complete with tape robots, full/incremental backup schedules and on-site/off-site tape storage.
For personal backup, for years I used scripts and rsync to backup to a private vps. These days still using scrips to copy key files (package lists, select /etc & /home files) to an SD card directory that’s sync’d with ODrive (GDrive client). Nextcloud or similar clients would work too. A nice side benefit is that sharing any file is easy, just by copying it to a sync’d directory and sharing through GDrive’s web interface (note that GDrive provides file versioning by default).
Also I’ve used Syncthing for both on-site and off-site mirroring. Syncthing supports file versioning and is a powerful multi-master-capable alternative to rsync.
Also, to those doing disk image Backups, do you create a 1:1 image of the disk including empty space? Or is there a way to run dd on a disk and write to an image without writing all the empty space?
It is posible to dd to a tar file.
fsarchiver
Edit: also look at Partclone “…provides utilities to back up and restore used-blocks of a partition…”
And technically dd isn’t even necessary, if you don’t care about the fine-tuning of block size, etc., even cat will do the job. For interactive partition cloning on identical sized partitions, I’m partial to pv with its nice progress meter, e.g.:
pv /dev/sda1 > /dev/sdb1
Edit: A digression on partition images, qemu-img can create (and convert, eliminating unused bytes) mountable compressed images (guestmount is an easy tool for this), suitable to receive backup data from tar, cpio, etc. And mksquashfs can create a highly compressed and mountable (read-only) image copy of a filesystem.