我的debian8开机时，总是出现下面的提示：

[ 908.954911] ata5.00: status: { DRDY ERR }
[ 923.285748] ata5.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
[ 923.285757] ata5.00: irq_stat 0x40000001
[ 923.285766] sr 4:0:0:0: CDB:
[ 923.285770] Get event status notification: 4a 01 00 00 10 00 00 00 08 00
[ 923.285791] ata5.00: cmd a0/00:00:00:08:00/00:00:00:00:00/a0 tag 24 pio 16392 in
res 51/54:03:00:08:00/00:03:00:08:00/a0 Emask 0x1 (device error)
[ 923.285796] ata5.00: status: { DRDY ERR }

查了资料说是磁盘需要修复。

e2fsck -a /dev/sda2
/dev/sda2 is mounted.
e2fsck: Cannot continue, aborting.

umount /dev/sda2
umount: /home: target is busy
(In some cases useful info about processes that
use the device is found by lsof(8) or fuser(1).)

请问，如何处理？