I’m particularly interested in low bandwidth solutions. My connection to the internet is pretty rough 20mbps down and 1mbps up with no option to upgrade.
That said, this isn’t limited to low bandwidth solutions.
I’m planning on redoing my entire setup soon to run on Kubernetes followed by expanding the scope of what my server does (Currently plex, a sftp server and local client backups). Before i do that i need a proper offsite backup solution.
The trick with SD cards is to not buy the cheap ones, they are horribly fragile (similarly faulty cheap usb sticks are more and more common, sadly). I’ve been using a 512Gb Sandisk Ultra microSDXC for 2 years, and it’s still rocking. It would not be a problem if it was to fail, anyway : I have several other backup storages, and I update that one daily, so I’ll know immediately when it fails, it’s not like I’ll realize it the day I’ll need it. On the plus side, it’s small enough to fit in a small 3d printed object, so that I can both keep it on myself and keep it hidden, just in case (it’s fully encrypted anyway, but still, better safe than sorry).