I have actually noticed a huge improvement in speed as the database gets large. Before, my pi would run smooth for about 7days (about 0.2 load average), then load averages would shoot way up to 1.5+ and hass would become very sluggish. The history would take minutes to load, and some automations would be ‘missed’ presumably because the pi was too busy talking to the sd (indicated by the high load average). Since moving to ssd, my database is now 1.4GB, well over a week of data, and it still runs snappy as a fresh install. Even loading 1week history takes just seconds to display… try that on sd! …and of course I won’t have to go down that depressing road of potential sd card failures either (which was my #1 motivation to go ssd). The only downside (for now until this gets merged in a hassos release image) is the update button doesn’t work, so any updates have to be done manually or through the dev channel.
Moving from sd to ssd for me was simple. I took a full snapshot and saved it to a PC. I flashed the ssd with the pi bootable image, booted up and let hassos complete install (my adapter required adding bootcode.bin and timeout to the otp memory). Once hass finished install, I setup my admin account, logged in, installed ssh plugin with a temporary password so I could ssh in to transfer my snapshot file from the PC to “/backup” (I avoid samba wherever possible, but you can use that if you prefer). Hit refresh on the snapshot screen (snapshot now displays), then did a restore (not wipe/restore). Then the pi rebooted and all was back to normal. The restore saved all of my complex configs… SSL certs, ssh tokens, and of course configuration.yaml stuff (and all of the linked files it may reference… like sensors.yaml, customization.yaml, secrets.yaml… etc files you have linked in your configuration.yaml). Note that some features you may be using may require a reboot or 2 to get up and running fully. So don’t start over from scratch just because say your mqtt sensors show as unavailable after the first reboot… they will show up after another reboot.