Asking for advice on how to move /edx in production environment

Software version: Juniper, Ubuntu 16.
Hi, last week I tried to move the /edx to a different disk. The steps i followed, in general, where these:

  • Create a new partition and new filesystem in the target disk.
  • Stop LMS and CMS services.
  • Create a backup of the server.
  • Copy /edx to target filessystem (cp -rp /edx/* /mnt/tmp)
  • Umount and then mount the target filesystem in /edx.
  • Change fstab
  • Reboot

It did not work as expected. I posted the problem and logs here. I am going to attempt this again in the near future, and thought to open a new thread and kindly ask for your suggestions. What steps am I missing? Thank you!