TeraStation Pro TS-HTGL/R5 Hard Drive replacement / upgrade

These are the steps I followed to replace the hard drives and upgrade the capacity on a TeraStation Pro TS-HTGL/R5. 

Note that I was completely replacing the drives for greater capacity, and deleted all the data from the array.  This scenario is for a TeraStation with 4 drives that are configured as RAID 5.  I used Western Digital Red drives with a capacity of 2.0TB and it worked fine.  I believe you can use even higher capacity (3+ TB) if you use Western Digital Red drives, but I have not confirmed this.  Please leave comments if you have any experience with larger drives in this unit.

First, I used Robocopy to archive the data from the TeraStation to a temporary backup location.  The options I used were "robocopy L:\Share D:\backup /E /B /R:2 /W:5"  Note that this will skip open files, so you need to make sure that no files are open on the TeraStation before doing this.  You MUST back up your data first when following this procedure or you will lose it all!

I updated the firmware by downloading the current firmware from the Buffalo web site.  Note that I had to update to version 1.33-1.32 first, then to the current firmware, 1.35-1.39.

After the files were backed up and the firmware was updated, I performed the following steps:

1. Shut down the TeraStation from the web interface.
2. Remove the 2nd - 4th drives.  You must leave the 1st drive in place for now in order to boot the TeraStation.
3. Turn the TeraStation back on and connect to the web interface.
4. Click on "Disk Management", then "Raid Setup" and click on any arrays that are defined.  Click "Delete Raid Array", and confirm it.
5. Click on "Disk Management", then "Disk Format".  Format the newly installed drives.  This will place the system files on the new drives, allowing it to boot when the 1st drive is replaced.
6. Shut down the TeraStation from the web interface.
7. Replace the 1st drive with the new one.
8. Turn the TeraStation back on.
9. Format the first drive using the same method for the previous drives.
10. Click "Disk Management", then "Raid Setup", then the icon for Raid Array 1.  Click the button to create a Raid 5 array.
11. Go to Shared Folders and re-create your shares.  It might take a while before it allows you to do this while it is initialized the new array.

After that, you can copy your files back using the reverse of the robocopy command, "robocopy D:\backup L:\Share /E /B /XC /XN /R:2 /W:5".  The XC and XN options prevent it from overwriting files that you might change on the TeraStation while it is still copying files (if you have to stop and restart robocopy for some reason).

The TeraStation will be slow for some time while it checks the array, this could take a few days if you are copying files and using it at the same time.