Once had problems with an internal drive so each device I run uses an external SSD/HDD. Anything important that has an “export data” or backup option such as Paperless I’ll export/backup & put that into Nextcloud. Nextcloud files are synced between multiple desktops, one of which then gets automatically backed up to a separate drive each week.

For all my other self host stuff I since deployed Kopia to perform nightly local backups of each thing I self host. Once per month a Kopia backup for each software gets moved to a separate drive.

On top of that, things I deem as particularly important get encrypted in Cryptomator & uploaded off site.

No doubt there’s probably better/easier ways but thats my current workflow.