如何得知到底是哪一顆硬碟有問題？

剛剛找到一個辦法了！
先找出來是哪一顆硬碟壞掉

# more /proc/mdstat
md0 : active raid6 sdl[11] sdn[13] sdk[10](F) sdo[14](S) sdm[12] sdh[7] sdf[5] sdc[2] sdj[9] sdg[6] sde[4] sda[0] sdd[3] sdb[1] sdi[8]
      21488642560 blocks super 1.2 level 6, 512k chunk, algorithm 2 [13/12] [UUUUUUUUUU_UU]
      [=>...................]  recovery =  7.3% (143145472/1953512960) finish=1996.5min speed=15112K/sec

從上面看出來是 sdk[10](F) 這顆壞掉
再用 smartctl 查出來這顆硬碟的序號

# smartctl --all /dev/sdk
smartctl 5.39.1 2010-01-28 r3054 [x86_64-unknown-linux-gnu] (local build)
Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net
=== START OF INFORMATION SECTION ===
Device Model:     ST2000DL003-9VT166
Serial Number:    5YD4SGVK

這樣我就可以順利找出來壞掉的硬碟是哪一顆了！