[RKDinOKC]

I have an old Mac Mini with a big fireproof waterproof external drive.

The mini is setup with Server for file serving. The internal drive is my Archive storage. The external drive is partitioned for Bootable backup of Archive Server, Bootable Backup for my Laptop, and Time Machine for my Laptop.

For bootable backup I use Tri-backup it has a nice scheduled changes only backup that runs nightly.

Server lets me set the Time Machine partition so it looks like a Time Capsule to the Laptop.

Use the Time Machine backups for recovery of individual files, or earlier file edits.
Use Bootable backups for catastrophic drive failure OR upgrading drives.

When I have upgraded my laptop drive, or the laptop itself I just make sure it has the newest system, then migrate from the bootable backup. Then reset the backups.

I do email and web site hosting and have a Mac Mini for email hosting and another for web hosting.
Have Time Machine and bootable backup partitions for each of them on my Archive Server as well.

Has saved my butt on a couple of occasions when boot drives were dying. Run Drive Genius to alert me to drive problems well before failure. Can just upgrade the drive, restore, and go about my merry way.