My Tablo won’t offer to format my drive. It just says the drive must be formatted. I can use a computer to do this. But what format to make it work? I tried FAT-32 and that doesn’t seem to work. Please help!
No you can’t. Make sure you’re using a device that works for initial setup ie) browser via PC or maybe mobile device - I don’t believe a Roku works.
Ultimately it’ll be formatted with an ext4 file system. tablo needs to format it’s own drive
It works! For those googling this problem, the situation seems to have fixed itself with a bit of time. The last steps I took were these: I repartitioned the hdd into one partition (it had already been one, but this did some erasing). I reset the Tablo, and when it was on, I plugged the hdd in. Still, the Seagate 2 TB “Backup Plus Slim” said the hard disk was “temporarily unavailable.” It listed the drive as " Seagate BUP Slim 0004 (2000 GB) ". Still it would NEVER give me the prompt to format the drive. Finally I just gave up and ate dinner. After dinner I fired up the Tablo portal and it immediately told me it recognized the drive and wanted to format it. Boom, it was done. My theory is that the Tablo had to query headquarters to get the correct instructions for the drive, which took a bit of time. Thankfully it’s all set. Love the Tablo!
If you search Tablo Comm unit Forums - you would have found others already dealt with the issue, offering solutions. So, be patient aka doing nothing works as well.
In the end I hope your tablo gives you no more hassle and you have great experience with it.
Thanks. I certainly searched the forums and tried everything listed, to no avail. No one suggested that I let it sit for an hour as a way of getting the Tablo to decide on its own to format my drive. Thus my reply suggesting as much for those who come after. 
A search format drive has a couple results, people waiting it out, and others just doing things in a different order…
as well as your discovery - yes let’s hope you can assist someowne