Do you rely on RAID as your NAS backup?

RAID provides a lot of storage with some protection against drive failure. If a drive fails in a 4-unit NAS, one can put in a new drive and rebuild the volume with no loss of data.

If the controller card fails in the NAS, not so simple!

I have my NAS backed up to an external USB drive. The OS on the NAS runs those backups automatically, but I had to set them up.

I just read this this morning and it may be what you're all looking for:
https://audiophilestyle.com/ca/bits-and-bytes/yottamaster-hc1-c3-excellent-storage-option-for-music-libraries-r958/

All the best,
Nonoise

Well, RAID is in fact very cool.... but usually requires an appliance, and the appliance itself can fail.

If you need high throughput access to a lot of storage, go with raid.

If you just need to back up your PC periodically, a single external disk will work.