ionice/renice setting for mdadm raid consistency check Ubuntu 20.04

Question

Is there a way to ionice and renice the raid consistency check Ubuntu 20.04? I found how to adjust schedule here: mdadm raid 5 pairity check control / new behaviors in Ubuntu 20.04
I have an array, 25TB raid 6, which takes 18 hours to check, so I need the system to be usable during that time. Ubuntu 18.04 had an --idle option for checkarray run from /etc/cron.d/mdadm, but I have not found anything similar for the systemd setup.

Answer 1

Not sure on renice, but on a small system I had it was taking 2 days and the system was just worthless during that time. So had to do something myself. Since mdadm can lower the max it checks which lowers the CPU... I changed it from - what I think is the default of 10000 to 2000 and then back when I was using it again. Here's the commands on ubuntu 22.04

echo 2000 | sudo tee /proc/sys/dev/raid/speed_limit_max
echo 10000 | sudo tee /proc/sys/dev/raid/speed_limit_max