Increasing Storage Space on PR2100

I have a PR2100 with (2) 6 TB drives in it. I have them set up where I have a total of 12 TB in Storage. I am running out of space. I just purchased (2) 12 TB Drives so I will now have a total of 24 TB. My question is how do I install the (2) 12tb drives and not lose any data.

@jlatorre620 the following KBA will help.

How to Upgrade the Drives on a My Cloud Device (RAID Expansion)

Answer ID 27421

I am still a little confused. I currently have my PR2100 set to spanning mode so my (2) 6tb drives are giving me 12TB of Space. Do I have to change it to Raid 1 before putting in the 12tb drives? Those instructions are not that clear. I need more of a step by step because I want to make sure this is done correctly and I do not lose any data etc. Thank you

You may also want to see the dedicated OS5 (v5.x firmware) Pro Series subforum where there is much additional discussion on the PR Series of devices where there may be similar discussions/questions related to your question.

OS5 My Cloud Pro Series

If still using the OS3 (v2.x) firmware on the PR2100, you may want to see the dedicated OS3 My Cloud Pro Series subforum for similar discussions to your question/issue.

OS3 My Cloud Pro Series

The two 6tb drives are configured as Spanning giving me 12tb of storage. I would like to to the same with the two 12tb drives so I will have 24tb of storage.

Yes I do

Backup the data before starting