Best firmware for RNDP2000 after OS6 upgrade

many thanks to the community for the guides on updating bios, backing up vpd, and the OS6 upgrade. i had a lot of nerves about the whole process because if it had bricked, i probably would have given up on having a nas altogether (too many other things going on to start over), but since sonos (and others) have dropped smb 1, i've had a little less to lose. it worked and at least for now i think everything is stable. the two bits of functionality i'd lost with os4 were my sonos music library (when they released their new dumpster fire app in may), and i wasn't able to browse photos on my tv through our oppo blu ray player anymore. (i suspect both of these were related to smb 1?) i haven't tried either yet as i'm still transferring files back to the nas, but fingers crossed.

a couple notes from my os6 upgrade yesterday...

• updating the bios: bios "version" is just a date. find it by downloading all your log files and opening bios_ver. On my pro 2, my version was "09/08/2010" (probably never updated until yesterday...also damn that's 14 years) and i believe "11/02/2011" is the most recent/one you want. search forums for the BIOS_Update_Package_0.5-x86 file.
• backing up vpd: this was the biggest headache for me. (https://community.netgear.com/t5/Using-your-ReadyNAS-in-Business/Backup-and-restore-of-VPD-file-for-legacy-ReadyNAS-running-oS6/m-p/2253308) i couldn't get telnet to work. connecting the readynas directly to my computer was what did it for me...i think the asus router was blocking telnet.
  -i downloaded putty, connected the readynas directly to my computer with ethernet, changed my computer's ip address to match the readynas (if nas ip is 192.168.50.50, change computer's ip to 192.168.50.40 or similar. ask chatgpt how to change your computer's ip address...), and followed the instructions.
  -once nas is booted in tech support mode, open raidar to see its ip address(es). open PuTTY (don't let it scare you), select telnet (which will automatically switch it to port 23), enter the ip address of the nas, and hit open. (if raidar shows multiple ip addresses you may need to try both to get it to work.)
  -it should prompt you for login info...type 'root' (no quotes) for the user and 'infr8ntdebug' for the password. the characters may or may not show up as you type...just type root and hit enter, then infr8ntdebug and hit enter. (or, if you have a certain add-on installed, the password might be your normal admin password?? but not sure about that..)
  -if you see a "#" that means you're connected. the only telnet command i wasn't clear on from sandshark's post was how to display the info for all disks at the beginning. (i.e. /dev/sda and /dev/sdb etc) The command that worked for me was  either 'sfdisk -1' or 'sfdisk -l' i forget which...but this article was helpful: https://linuxhandbook.com/linux-list-disks/
  -from there everything in sandshark's post was straightforward. after unmounting the usb, i powered down the nas (manually) and powered it back on.
• when performing the os6 update, it looks like older versions of the instructions said to upload both the 'prep4tor6' and 'r4tor6' using the firmware update tool. then later, the recommendation changed to upload the 'prep4tor6' with the add-on tool, then 'r4tor6' using the firmware update tool. can confirm that the latter worked on my pro 2.
• also uh...when you log in to admin for the first time and change your password, make sure caps lock isn't on. lol. but also (in addition to my recent caps lock problem), i swear i remember having an admin password issue after an update years ago. i was going to wait for the factory reset/resync (which had it's own issues..see below) and then use the boot menu to do an os reinstall (not knowing if it would put me back to os4 or reinstall os6...) to reset the admin password, but then i tried caps lock and didn't need to....
• once the nas started re-syncing for the factory reset, it was taking forever. (i.e. 2 hours for 1 percent...would have taken over a week at that rate, but probably would have hung itself first. i'm using a pair of WD 3TB (cmr) red drives.) i've run into this once before on this nas, so i'm thinking it might be a "rare-but-not-uncommon" issue? in any case, since it's a factory reset the data is lost anyway, so i manually powered down the unit, turned it back on, and it started resyncing again much faster. it finished overnight in about 8 hours. hope this is helpful to somebody!