Can't create RAID 1 when adding second drive

[JHASUSTOR]

Hi,
I have the AS5202T. I recently maxed out the two x 4TB drives (set to RAID 1) that I had installed in the NAS. I picked up the only single 12TB drive locally and was awaiting the second 12TB to be shipped. In the mean time I did the following:
1. backed the data of the 4TB drive to an external drive.
2. removed the two 4TB drive out of the AS5205T
3. inserted only the single 12TB drive into slot #1 that I had on hand at the time
4. copied the data from the external drive to the now single 12TB drive in the AS5205T. Everything copied as expected.

Here's where the situation gets confusing. The second 12T drive arrived. I placed the drive into slot #2. I went into STORAGE MANAGER and clicked on Create. I chose ADVANCED SETP BUT the only option I have is SINGLE. The other RAID options are light grey and I cannot select them. What can I do to copy drive 1 over to drive 2 and establish RAID 1? Do I have to remove drive 1 as well and start from the beginning? If I remove drive 1 and set the two as RAID 1, will I loose all the data on drive 1? It took 3 days to copy this over so hoping I don't have to repeat the process again.

Thanks in advance for reading the lengthy question, hoping to give all the necessary details.

[Nazar78]

You were using the older 12tb as a single drive hence you can't convert it to raid 1 as they have different header information. Unfortunately from ADM, you'll need to reinitialize the both 12tb as a new raid 1. But unofficially you should be able pull this off by creating the raid 1 with only the newer 12tb, copy the files while in degraded mode, add the older 12tb to complete the rebuild. I've never tried this on a NAS but other target long ago. Do a research on this prior also backup.

Edited: ignore my reply, must have been sleepy, yes you can migrate single to raid see orion's post.

[orion]

You should be able to change your current single 12TB volume to RAID-1: https://www.asustor.com/en-gb/online/Co ... ?topic=352. You should not create another volume for the second 12 TB disk. Go to manage button of volume-1.