解决umount target is busy，input/output error

重新挂载一次
sudo mkdir /mnt/mydisk
 sudo mount /dev/sda9 /mnt/mydisk
 sudo umount /dev/sda9
 以上 通用于ext2, ext4 
[root@test01 mnt]# vim /etc/profile.d/autologout.sh
TMOUT=10
 readonly TMOUT
 export TMOUT加上执行权限
[root@test01 mnt]# chmod +x /etc/profile.d/autologout.sh
重启系统：reboot
无效要删除掉脚本 执行第一种方法
 
Same issue. Let's see if dmesg tells us something useful:
dmesg 
 [116836.420063] EXT4-fs error (device dm-5): ext4_lookup: deleted inode referenced: 24274320 
 [116842.656399] EXT4-fs error (device dm-5): ext4_lookup: deleted inode referenced: 24400033 
 [116842.574064] EXT4-fs error (device dm-5): ext4_lookup: deleted inode referenced: 24273584 umount /backup 

fsck.ext4 /dev/mapper/vg0-backup 
 e2fsck 1.41.12 (17-May-2010) 
 /dev/mapper/vg0-backup contains a file system with errors, check forced. 
 Pass 1: Checking inodes, blocks, and sizes 
 Pass 2: Checking directory structure 

 Entry '1360095843,S=4225,W=4321:2,S' in /rsnapshot/daily.9/localhost/home/mail/web98p8/Maildir/cur (8674221) has deleted/unused inode 24274320.  Clear? yes 

 Entry '2' in /rsnapshot/daily.9/localhost/var/www/web136/files/g2data/cache/entity/3 (24400027) has deleted/unused inode 24400033.  Clear? yes 

 Entry '1359872706,S=12695,W=12855:2,S' in /rsnapshot/daily.9/localhost/home/mail/web98p1/Maildir/cur (8671256) has deleted/unused inode 24273584.  Clear? yesPass 3: Checking directory connectivity 

 Pass 4: Checking reference counts 
 Inode 939825 ref count is 10, should be 9.  Fix? yes 
 Inode 939826 ref count is 10, should be 9.  Fix? yes 
 Inode 939827 ref count is 10, should be 9.  Fix? yes 
 Inode 939843 ref count is 10, should be 9.  Fix? yesPass 5: Checking group summary information 
 Block bitmap differences:  -(97030728--97030731) -(97033838--97033839) -97529271 
 Fix? yes 

 Free blocks count wrong for group #2961 (3626, counted=3632). 
 Fix? yes 

 Free blocks count wrong for group #2976 (8930, counted=8931). 
 Fix? yes 

 Free blocks count wrong (50341877, counted=50341884). 
 Fix? yes 

 Inode bitmap differences:  -24273584 -24274320 -24400033 
 Fix? yes 

 Free inodes count wrong for group #2963 (2017, counted=2019). 
 Fix? yes 

 Free inodes count wrong for group #2978 (3021, counted=3022). 
 Fix? yes 

 Directories count wrong for group #2978 (4051, counted=4050). 
 Fix? yes 

 Free inodes count wrong (26902779, counted=26902782). 
 Fix? yes 

 /dev/mapper/vg0-backup: ***** FILE SYSTEM WAS MODIFIED ***** 
 /dev/mapper/vg0-backup: 5865218/32768000 files (0.1% non-contiguous), 80730116/131072000 blocks