Yep, 18 TB will need -b 8192.
You can also throw some block count (-c 128).
Most importantly, you do that from a tmux session, so your commands are
tmux
badblocks -b 8192 -c 128 -vws /dev/sdX
and then you let it cook for… what it takes (8-10 days?).
For once, you can perfectly do this from the webshell 
curtesy of tmux.
To check where it is, as you only have one tmux session running in this scenario, just type
tmux attach.
So that I am 100%
tmux - Enter
badblocks -b 8192 -c 128 -vws /dev/sda - Enter
and
tmux attach - Enter, to check up on progress?
And leave the NAS on for a week or so?
Just don’t fuckup on which drive you’re running it on. Check 5 times that it is indeed “sda” or whatever.
Those labels can change between reboots & badblocks is destructive.
Roger, shall check multiple times.
And once more, thanks for all the help everyone, I appreciate it.
…and you still have the final 0x00 pass to go through!
Well, at least you’ll have more confidence that this drive might be fine after all.
Few more days then I am guessing?
Well once badblocks is done, you can run another smart long to be realllllly sure 
Waiting to walk past this room in the morning and not having it glow. Obnoxious RGB NAS was a funny idea until it’s on all the time.
Yeah, i was silly enough to reuse an old case instead of getting a rack… So now i have 3 more cases for other builds instead of a rack (I’m a fast learner!)
The good news is that i have individual rgb controllers in each so i don’t have a light show if i don’t want one
Careful: Once the rack is full enough, there are more LEDs blinking at you than any poorly thought out RGB NAS.
But think of the savings on Xmas decorations… 
(Halloween is already covered.)
Also just swapped in a new CPU cooler since the idea of Zalman being back, and making a jet engine was funny.
