I am new to unraid and command line computing in general and I'm hoping someone can help.

 

I already had an array up and running with 3 new 18TB drives, but started running low on space so I grabbed old 6TB and old 4TB drives out of my windows machine. After plugging them in and starting up unraid, they showed up listed in the Disk Devices section near the bottom of the Main tab. I have the 3 'unassigned devices' plugins installed. There was no option to preclear or format, so after a little google searching I landing on using fdisk to delete partions. That allowed me to use the preclear function on both drives yesterday. However, I still don't have the option to format the drives in the unraid GUI. No file system is showing. If I add them to the array it says 'unmountable unsupported partition layout'. What do I need to do next?

Do you have destructive mode enabled for UD?

Ok destructive mode was not enabled in unassigned devices. I turned that on and now I have the option to clear disk (red x). I assume I do that next, and after that do I format the disk or do I do a new preclear since the clear disk will remove the signature for the previous preclear? Also, I added the disks to the array. What is the best order of operations when in my current situation? The array is stopped, is there a way to remove those disks from the array while I do the next steps (other than just selecting 'none' from the dropdown menu for the disk selection options)? Or is that not necessary? I can't start the array when I change the array disk to 'none' for these disks I'm trying to format, so it would be great if I could still use my server if I need to do the preclear.

If you format a precleared disk you will remove the preclear signature, if you plan to add the disk to the array don't format with UD, add it and format in the array.

Sorry for resurrecting this post but I'm on version 7.2.0 and I can't format drives that have been precleared, even though I have destructive mode enabled

And the reason why I want to format is because if I simply create a new config, select the drives and format them, they always get formatted in XFS, even tough I also have this option enabled

Am I doing something wrong or this is completely bugged?

PS: Btw, what's the reason for precleared disks so complicated to format them? What's so special about a precleared disk?

Edited November 7, 2025Nov 7 by s1l3nce

9 hours ago, s1l3nce said:

Sorry for resurrecting this post but I'm on version 7.2.0 and I can't format drives that have been precleared, even though I have destructive mode enabled

Destructive mode is a UD thing, please clarify why you cannot format the drive using the GUI.

St

3 hours ago, JorgeB said:

Destructive mode is a UD thing, please clarify why you cannot format the drive using the GUI.

Strangely enough, after rebooting the system I can format all of them.