@Gabz I'm on the 15 day BackBlaze trial. 5 days in, almost have 750 gigs of photos and lossless music backed up from external drive connected to MBA. This drive backs up my NAS. Seems like the way to go. There are (age limits)[https://help.backblaze.com/hc/en-us/articles/217665398-Backing-up-External-Hard-Drives] for external drives though so got to be sure and connect it for back up every 30 days. BackBlaze will remind you, fortunately.
@Gabz not sure if this helps but I detailed my backup strategy here: islandinthenet.com/photograp...
@Gabz Last year adopted Arq for offsite backups. I'm using mine with Amazon Glacier so it is pretty cost effective. I run it manually on a recurring basis because I also have iCloud storage as well as local backups over the network to both Time Machine and Carbon Copy Cloner images on a NAS. I don't consider Arq/AWS as anything other than a worst-case solution (everything local stolen or destroyed) because it is slow for a large scale restore and expensive compared to my other backups.
@Gabz Backblaze is awesome. I also use Chronosync to set up multiple additional layers of redundancy (my archive Drobo is mirrored to a second Drobo which is mirrored via Chronoagent to a Drobo in my mother’s apartment). It doesn’t handle APFS snapshots, but other than that, I’m a huge fan. (They even have a useful trick to guard against ransomware.
@Gabz I set up Backblaze for my laptop and foe my wife’s work computer. It’s been solid since. I get lots of reminders. Haven’t had to restore but when I have tested for retrieving files it worked. I saw an alternative posted to MB recently; will look for link and share.