LVM: on simple raid1 with two legs Cpy%Sync never reaches 100% and always stays at 99.99%

On simple lvm raid1 with two legs Cpy%Sync never reaches 100% and always stays at 99.99%. lvm> lvs -a -o name,raid_sync_action,sync_percent LV SyncAction Cpy%Sync safe idle 99,99 [safe_rimage_0] [safe_rimage_1] [safe_rmeta_0] [safe_rmeta_1] How can I troubleshot and fix this? It is preventing me from issue other commands, and probably doesn't handle failures properly. One of the failing commands is: lvm> lvchange --writemostly /dev/sdd1:y vg/safe Unable to change writemostly on vg/safe while it is not in-sync.