A Linux software raid is free, I'm not going to buy a PERC š«
Discussion
Oh phew. Still not sure you actually need to double the blockchain data, you just need to point the channel backup save directory to a separate disk
Soft raid doesn't do a checksum of the data. It will likely save you from HDD failure but, it won't from an unlucky HDD error. Plus while waiting for resynchronisation you will have just a single copy and will be super vulnerable. I am second for backups. Preferably more than one. Raid is not a backup.
Trust me. I have no idea how to run a node but I hoard many TB of photos and for years I didn't lose anything. I use raid1 sometimes for things I don't really care to lose but I would prefer to avoid it.