Hey there, I'm very new to unRAID and a lot of this stuff is still going over my head on initial setup. I'm moving my Plex server from an old/failing Synology NAS to a new dedicated server build using unRAID. I have a total of 10 6TB drives (old drives that I got for a good deal) that all spin up and have goo SMART readings. Currently there is no data on these 10 drives, my Plex files are safely housed on the Synology NAS for now, but it's only a matter of time for that. I followed Elevated Systems guide for how to set up my server but I'm having difficulties getting my hard drives to cooperate. For some reason only 2 of the drives are recognized when I start up the array:

I've tried starting the array in maintenance mode and running xfs_repair but unRAID is giving me an error I'm not sure how to fix:

I've tried perusing the forums and Google but I haven't found anything that seems to help so far. Or possibly nothing that I've been able to follow closely enough to execute properly.

Any help would be much appreciated. I can post whatever logs you need/want to see. Thank you in advance.

Did you let Unraid format the drives after adding them to the array?

1 hour ago, trurl said:

Did you let Unraid format the drives after adding them to the array?

Thanks for the reply.

I did, yes. It still says they are unmountable

Edited November 3, 2025Nov 3 by mattphillips43

did you also hit the "yes, I want to do this" Box???

pls retry and then post diagnostics afterwards

19 hours ago, MAM59 said:

did you also hit the "yes, I want to do this" Box???

pls retry and then post diagnostics afterwards

Yes, I did do that. Here are the diagnostics:
phillips-unraid-diagnostics-20251103-2010.zip

I see...

I guess:

This looks like to be the problem. The "unmountable" disks are only 16360 sectors in size, too small for xfs (or any other filesystem).

Looks like already the partinioning failed.

Strange

I guess this is something for @jorge I can't help you with SAS drives and controllers, sorry.

Edited November 4, 2025Nov 4 by MAM59

By default, Unraid uses the largest existing partition for new arrays, which in this case is too small, do a new config, then click on each disk and "erase", then start the array, and they should now format.

6 hours ago, JorgeB said:

By default, Unraid uses the largest existing partition for new arrays, which in this case is too small, do a new config, then click on each disk and "erase", then start the array, and they should now format.

Thank you both for the quick responses. Just to make sure I'm following the instructions, looks like I stop the array -> Tools -> New Config. Should I preserve anything from the existing config or just a full reset?

You can preserve all the assignments.

Thanks, I did that and it seemed to format just fine. It's running through a new parity check now but so far no errors. All HDDs are showing with their full capacities with a total array capacity of about ~47TB.

Out of curiousity, what is the difference from doing erase vs. a normal format and why did I need to create a new config to do it? Does format only work on the current partition whereas erase just resets the drive to ground zero?

Thanks again!

12 hours ago, mattphillips43 said:

Out of curiousity, what is the difference from doing erase vs. a normal format and why did I need to create a new config to do it?

For a new array, Unraid keeps the existing partitions. This is to try and import any existing data if it's using one of the supported filesystems, but then, even when the disks are reformatted, the partitions are kept, I don't remember the exact details, but it has to do with how the md driver is initiated. It would be technically complicated to repartition them at that time. If you erase the disks first, there won't be a partition layout, and in that case, Unraid creates the standard layout.