Hi!
I’ve been trying to mount an externall hdd to my rp4 (I’m running linux armv7l HassOS 3.8) but without any success… Is it even possible? Because I’ve read some related topics and the answers were that’s not or it was too complicated for me. Hope I will get straight information here 
I’m following this guide https://www.home-assistant.io/docs/ecosystem/backup/backup_usb/
but after dmesg command I get this:
The drive is there, but looks like there is no folder dev/sda
Is there any solution?