I have got an external hard drive (A) that contains my iTunes & Aperture libraries. It's not always plugged to my MacBook.
What's the best way to make a backup of it on another external hard drive (B) ?
Wanted features :
- fully automated (that executes itself hourly, or something like that)
- incremental (in order to be fast)
- only activates when both disks (A & B) are plugged in
- works with multiple backup disks (in order to have a backup at home and another at work)
- discrete indication that a backup is in progress
- ability to pause or stop backup (useful if I am in a hurry and have to disconnect external drives)
It would be nice if backup disks could be networked, but that's not mandatory.
I would have loved to use Time Machine in order to have an history, but it doesn't seem to work well with external hard drives that aren't always connected and I don't trust it for that use case (my internal SSD is backed up thanks to Time Machine, though).
Online backups aren't adequate because I have a very poor internet connection.