You have problems with automatic rebuilding raid 1 (md) on debian (resync=PENDING)? mdX : active (auto-read-only) raid1 sdaY[0] sdbY[1] 2000000 blocks [2/2] [UU] resync=PENDING do; mdadm –readwrite /dev/mdX and the process of rebuilding starts [===>…]  resync = 16.2% (324736/2000000) finish=0.6min speed=46390K/sec