[CentOS] mount bind problem

Tue Apr 12 06:17:13 UTC 2016
望月忠雄 <tadao at creative-japan.org>

On CentOS release 6.7, there's file system problem.
Aftert reboot /home is set under /home (/home/home) like followings.

# ls -l /home
total 48
-rw------- 1 root  root   7168 Nov 15 19:10 aquota.group
-rw------- 1 root  root   7168 Jan 25 11:09 aquota.user
drwxr-x--- 2 root  root   4096 Jan 18 21:55 backups
drwxr-xr-x 4 root  root   4096 Jan  1 11:59 home
drwxr-xr-x 8 root  root   4096 Apr  5 01:10 log
drwx------ 2 root  root  16384 Nov 15 18:58 lost+found
drwxr-xr-x 6 mysql mysql  4096 Dec 13 22:34 mysql


# df
Filesystem           1K-blocks    Used Available Use% Mounted on
/dev/mapper/VolGroup-lv_root
                      12778200 2946824   9175608  25% /
tmpfs                   961176       0    961176   0% /dev/shm
/dev/vda1               487652  205564    256488  45% /boot
/dev/vdb              41153856  549492  38507212   2% /mnt/extradiskA
/dev/vdb              41153856  549492  38507212   2% /home

I have set on fstab /home with 'mount bind' but it seems like bind is not
effective.

/etc/fstab is following.

# cat /etc/fstab

#
# /etc/fstab
# Created by anaconda on Mon Jul 28 08:21:01 2014
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/VolGroup-lv_root /                       ext4
 defaults,usrquota,grpquota        1 1
UUID=9a855356-ee00-4ae7-a185-226566ce1dba /boot                   ext4
 defaults        1 2
UUID=093c9b95-8336-4682-9927-132dbdf2f082 /mnt/extradiskA     ext4
 defaults,usrquota,grpquota      1 2
/dev/mapper/VolGroup-lv_swap swap                    swap    defaults
 0 0
tmpfs                   /dev/shm                tmpfs   defaults        0 0
devpts                  /dev/pts                devpts  gid=5,mode=620  0 0
sysfs                   /sys                    sysfs   defaults        0 0
proc                    /proc                   proc    defaults        0 0
/mnt/extradiskA/home    /home                   none    bind            0 0
/mnt/extradiskA/log     /var/log                none    bind            0 0
/mnt/extradiskA/mysql    /var/lib/mysql         none    bind            0 0
/mnt/extradiskA/.backup /.backup                none    bind            0 0
/mnt/extradiskA/.daily_backup  /.daily_backup   none    bind            0 0
/mnt/extradiskA/backups  /var/backups           none    bind            0 0