MyCloud EX2 Ultra - Unable to mount the USB device

csabaoszkar · November 28, 2023, 10:56am

Hi guys,

I am relatively new to this environment, so please don’t shoot me if I ask stupid questions.

I recently got 4x 6TB WD RED from my employer so I purchased a WD MyCloudEX2Ultra for some home backup purposes. The installation went just fine, I added two HDDs to the 2 bays, they got formatted accordingly and everything works fine. My problem is with the 2 other HDDs. I have an external SATA slot housing where I can attach them, they get separate power and an USB connection from where I have attached it to the NAS.

I have read already on these forums, that the USB 3.0 doesn’t deliver enough power to the external USB hard drives, but mine is separately powered up, so theoretically, it should work. When I attached it to the NAS, I got an error message in the notification are, saying “Unable to mount the USB device. Please check the USB device. Code:1124”

Now, I have also read here, that the external USB drives need to be specially formatted in order to get correctly recognized. The problem with this part is, that I have tried to format it from my Windows 11 machine, however, it only recognizes 2TBs from the 6TBs, none of the formatting options (NTFS, exFAT, FAT32, etc.) worked. Apparently, it is due the HDD function as it is intended to be used with NAS only (got this info also from a forum somewhere, please correct me if it is wrong).

I tried to attach my 1TB USB memory stick in the NAS USB slots, that didn’t work either.
I restarted the device, it didn’t resolve the issue.
I upgraded the firmware (it was the first thing to do when I unpacked it), it is currently the version 5.27.157

Could someone please point me in the right direction?
Thank you all in advance.

Cerberus · November 28, 2023, 11:01am

It sounds like the drives are partitioned using MBR. They must be GPT partitioned or it won’t work.

csabaoszkar · November 28, 2023, 11:15am

Hello Cerberus, Thank you for your reply

Yes, I missed that information in my initial message.
I tried both ways:

transformed the drive to GPT from Windows Computer Management - tested it, still showed 2TB, and the NAS didn’t recognize it
tried to do the same with DISKPART cmd, fully formatted it, changed to GPT, and the same result

According to the links you shared, the My Cloud EX2 Ultra should support all the file systems.
What I didn’t try yet, is after having the NAS format the drives, to its need and environment, to remove from the bay and attach it to the NAS via USB.
Does that make any sence?

Cerberus · November 28, 2023, 11:20am

There’s no need to have the NAS format the drives. Just partition them using GPT, then format them using NTFS and it should work. It’s what I use.

csabaoszkar · November 29, 2023, 6:22am

Hello Cerberus,

Thank you for your advice, it seems that indeed it was the solution for this issue, as I could identify it and then created a workaround solution.

Apparently, my desktop computer has some USB driver problems (although it says that all of them are up to date), and that was the reason it couldn’t correctly clean and convert to GPT both in DiskPart and in Computer Management. After attaching the drive to an another laptop, right after listing the disks in DiskPart, the correct HDD size has been shown, so after that I could correctly format the drive, and convert it to GPT style.

Still, it wasn’t recognized by the NAS:

So I wanted to test it with other drives. I had two, 3TB WD Passports, I have cleaned them, converted to GPT, and they were instantly recognized by the NAS as soon as I connected them to the USB slot. I guess at this point I can blame the Expansion Desk, that is connecting the 6TB HDD from SATA to USB. The laptop, that is managing my backups does recognize it as a 6TB HDD, so I simply swapped the 6TB HDDs with the 3TB Passports, and now I have a workaround solution, however, it still remains a mistery why the NAS doesn’t recognize it.

Thank you again for the instructions, much appreciated!