Drobo

Protection upon drive size change

I upgraded my drobo from 1tb drives to 2tb drives, doing the first 3 at first, then the last one.

I used to have approx 60% data, 40% protection.

Now, with 8tb total, I have this:
5.44tb data
1.83tb protection

I only have 1.71 tb used. It also went from one “mapped” drive to two.

Now it doesn’t seem like I have enough protection. How do I fix this?

“protection” is always equal to your largest disk

your current setup is exactly correct…

6TB of data - 2TB protection (assuming 1,000GB to a TB which is wrong but a differnet issue)

It went to TWO mapped drives? What is your Drobo volume size configured as? Maybe this will inform.
http://support.drobo.com/app/answers/detail/a_id/23

If Disk Space Exceeds Volume Size

If the amount of available protected storage*** in your Drobo storage device ever exceeds the size of the volume that you picked originally during installation (when you add one or more additional disk drives), then the Drobo device will automatically create a new volume of the same size as the original volume on 1st and 2nd generation Drobos. Your Drobo handles this situation automatically. When the total storage offered by the inserted drives exceeds your volume size, Drobo Dashboard will automatically create a second volume (of the same size) which appears as another volume icon on the Mac’s Desktop or as a new drive letter or partition on the PC. You will be asked to format and name the new volume. Formatting the second volume/partition will not affect the first.

If you are using Drobo S, DroboPro or DroboElite, you will be prompted by Drobo Dashboard to create another volume through the Volume Management facility.

*** This is the same as the “Available for data” section shown by the Drobolator and on the Drobo Dashboard under “How is my storage being used?”

Maintaining a Single Volume

If you want to maintain all data on a single volume rather than on multiple volumes, you’ll need to migrate the data onto another Drobo or storage device, reformat the original Drobo device to the volume size of your choice, and then move the data back. Many customers choose the largest capacity available during initial setup to avoid having to move such large amounts of data around.

Thin Provisioning

You can format your Drobo device’s volume size as 1TB, 2TB, 4TB, 8TB or 16TB (even without having that much disk space). This ability to format your volume to be larger than available disk space is called “thin provisioning.” It allows you to grow into a single, large volume over time rather than needing multiple smaller volumes. However, keep in mind some operating systems have a 2TB per-volume limit (as detailed in the chart above).

Note: Even though your operating system may prompt you to format your volume, it is better to use Drobo Dashboard for formatting. Drobo Dashboard allows you to format your volume to a size larger than the available disk space (thin provisioning).