I was wondering what is the right way\procedure to add a second hard disk\ssd\nvme to bazzite and make it recognized by steam as a second steam library where you can install games etc.?
I thought the way would be use Disks (in the gnome deck version) and format it into btrfs, but doesn’t seem to show up in steam gamemode.
So what is it the right way to add a second hard disk and mount it automatically at every boot?
Hello, from my experience you are able to auto mount your SSD using the Gnome Disks software that you mentioned in your post. You will need to do the following: first select your partition then you click on the settings button → Edit mount options → Uncheck the user session defaults. Here you will find options to mount your SSD at system startup and you may indicate where you would like your SSD to be mounted to. If you are unfamiliar with these options I would suggest to look up a guide first before manipulating the settings haha. The user session default may be already what you need. In my case, I use a microSD for my Steam Deck, and it auto mounts without me needing to change any of the options.
Once you figure out how to auto mount your SSD or if it is already auto mounting at system startup then you will then need to open Steam in desktop mode. Next click Steam (top left) → settings → storage. On this page click the drop down menu button and click add drive. Here you will select your SSD. If you want it as your default storage for games hit the … button and select default. I hope this helps. Cheers!
thank you very much, yep the first part I did it no problem, I was missing how to add it to steam, and your suggestion to open it up in desktop mode did the trick thank you very much 
I love bazzite seems pretty awesome\stable so far