Shouldn't /proc/mdstat have [UUUUU] instead of [_UUUU]? Perhaps this is running in degraded mode. Also, you have 'algorithm 0', whereas my raid5 has 'algorithm 2', which is the left-symmetric parity algorithm. Andy > cat /proc/mdstat gives: > > Personalities : [raid0] [raid5] > read_ahead 1024 sectors > md0 : active raid5 hdk1[4] hdi1[3] hdg1[2] hde1[1] hdc1[0] > 468872704 blocks level 5, 128k chunk, algorithm 0 [5/5] [_UUUU] > unused devices: <none> - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html