I’ve been pondering making an instruction for the same reason. I kind of feel if you don’t know how to figure this one out by yourself, you probably shouldn’t so it. Additionally, while it helps with performance, it definitely adds an additional point of failure to your node. Because now HDD failure is not the only thing that can take your node down. The SSD failing can as well.
So I think if we are going to make an instruction available as a separate post, we should include these warnings and caveats. And probably dissuade people from doing this unless they know it’s absolutely necessary for their setup. I mean, I know what needs to be done and have done it for 2 nodes now. But… I was a little in a hurry on the second one and forgot to copy the db’s. Caught is quickly enough and merged them together again (don’t ask how… it’s a lot of manual work, just avoid this). It’s too easy to mess up and not easy to fix problems afterwards. The only reason I’m doing this is because I’m using devices that almost certainly won’t be able to keep up otherwise after they are vetted and getting the full load. Additionally, I use RAID on the db disk, so there is protection against drive failure to mitigate the risk of relying on more than 1 disk for 1 node.