Remove the failed partition /dev/sde1
mdadm --manage /dev/md99 -r /dev/sde1
mdadm: hot removed /dev/sde1 from /dev/md99
Now add another drive back to replace it:
# mdadm --manage /dev/md99 -a /dev/sdf1
mdadm: added /dev/sdf1
A "cat /proc/mdstat" should show it resyncing if all is well.........
Tired of checking iotop and seeing that your drbd partition is using 99.99% of io all the time and finding your drbd device performs slow in general?
This is especially an issue in versions of DRBD in the 8.3 tree in particular one documented case is on "8.3.13" but it likely applies to other devices.
The symptoms are that resyncing is fine and normal but any reasonable amount of activity is very slow and lagged and creates a high server load and con........