[REQUEST] md raid array status

[reukiodo]

Is your feature request related to a problem? Please describe.
It would be nice to see when a RAID storage is rebuilding, and how far along it is. It could be even more informative to have each drive represented in the braille dots to show healthy drives of the raid.

Describe the solution you'd like
I imagine that there could be a bar in that storage's section not too dissimilar to Used and Free which could show the percentage complete in the bar and the end number could be the rebuild rate. I assume in the default theme the color bar would change from red (0%) to green (100%).
Something akin to:
RAID-⠿-⠽-----------------------10.9TB
Used: 31% [][][][][]------------- 3.42TB
Free: 69% [][][][][][][][][][][]------ 7.49TB
Build: 45% [][][][][][][][]--------- 22MB/s

Where ⠽ shows that drive 2 is down from mdstat's [U_UUUUU] display.

Describe alternatives you've considered
Right now I have a separate terminal window with watch -n1 cat /proc/mdstat to show the RAID rebuild.

Additional context
This might also apply to btrfs or ZFS RAIDs? I don't have experience with those so I do not know how those disk failures are detected or if they even share rebuild information.