Please first check the data storage directories of your MongoDB. While doing some crazy tests and more or less intentionally made the MongoDB go crash I found at times that it "forgot" about the available data, even though there were still kind of big files probably with all the data. I don't know how to recover from there but I assume there would be some articles out there in the internet helping you with it.
But yeah, mongodump, borg backup, lftp synchronize to remote drive (or similar). Every day. And if you're at it, make sure the backups on your local computer are working as intended as well 😉
I would like to know if there is a recommended way to merge two nodebb forums ?
I converted some threads using the mybb import plugin but the original db was so big I ran into issues (plugin crashing) and couldn't convert the whole forum. I limited my import to the most popular threads, keeping only posts less than 1y old and it worked. But it was so time consuming that I decided to upgrade nodebb instance and made it available to users. Since the import plugin requires nodebb v1.0.0 my idea would be to create a new nodebb instance with its own mongodb and import the remaining threads/posts, then upgrade it to the same level as our "production" one and try to merge the imported threads to the "live" nodebb.
Has any nodebb merge been done before ? Suggestions ?