Back Up Data to 12 TB Drive Failed

[mahesh]

Hello

I recently bought a new Seagate Ironwolf drive. I have it on an external mount with its own power connected to a computer running Ubuntu 20.04.

I ran "Disks" and the drive checked OK. I then went into GPARTED and selected Create partition table.

I selected msdos.

I then created a single ext4 partition for the entire drive.

After, I copied a few TBs of data into the drive and all seemed okay. When I went to confirm if the backed up files were intact and could be played, the computer could not open them.

I thought I should just unmount the drive, power down the external mount, and try again.

Once I powered back up, the computer acknowledged that the hdd connected, but that's it.

DISKS SMART test says everything is OK

GPARTED says that the drive is unallocated for 10.91 TB.

I'm not sure what happened...or what I did wrong.