Ok, so the next step is to see what happened to your partition tables. Looking at the RAID Wiki (https://raid.wiki.kernel.org) can you do the following on /dev/sdc: dd if=/dev/sdc bs=4k count=4k |hexdump -C |head -n1000 The idea is to look for the EFI or other partition table and figure out what offset it is actually at. Also, let's look at the partitions on both disks, so please do: fdisk -l /dev/sdc fdisk -l /dev/sdd as well. Please just cut'n'paste the command and it's output, don't edit or mash together or run all the commands at once seperated with ';', because it makes it harder for us to help you since we have to re-order the output. I really want to see something like this: > sudo fdisk -l /dev/sda Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0xaacd0512 Device Boot Start End Sectors Size Id Type /dev/sda1 2048 3907029167 3907027120 1.8T 83 Linux > sudo fdisk -l /dev/sdb Disk /dev/sdb: 1.8 TiB, 2000398934016 bytes, 3907029168 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0x00000000 Device Boot Start End Sectors Size Id Type /dev/sdb1 63 3907024064 3907024002 1.8T 83 Linux quad:~/CircuitPython/snd-bar-ctlr> John
