I have a shared web server that users can SSH / SFTP into to access their web content.  Each users home directory is in a change root, and I use "mount -o bind" to put their respective webpage's document root into their home directory.  Recently I was made aware that the contents of the mount's source are not the same as the mount point's, which I don't see how that is possible.

The file system is 3 virtual disks...each part of the same volume group.  I have three LVMs, "/" , "/chroot" , and "/var".

Here's the entry in /etc/fstab...

/var/www/example.com   /chroot/home/user1/example.com   none    defaults,bind   0   0

The mount is active, yet running a recursive diff between "/var/www/example.com" and "/chroot/home/user1/example.com" shows numerous differences.

Here's "mount" output
------------------
/dev/mapper/VolGroup00-LogVol00 on / type ext3 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/dev/mapper/VolGroup00-lv_chroot on /chroot type ext3 (rw)
/var/www/example.com on /chroot/home/user1/example.com type none (rw,bind)
/dev/mapper/VolGroup00-lv_var on /var type ext3 (rw)


I honestly have no idea how this is possible.  Is using "mount -o bind" not the best method to give a chrooted user access to a single directory outside the chroot?  Would it be better to leave the web root in the chroot and have Apache (outside chroot) reference that location?

Thanks
- Trey