I ran into a huge issue. I planned to replace the motherboard in my HTPC, it was assembled but it turned out that my new mb is faulty and I had to put back the old one. My old Ubuntu 20.04.2 is booted, all drives mounted except the RAID 1 ARRAY (sdc and sdd). I figured it out that the new motherboard's UEFI bios probably deleted the superblocks from the raided HDDs. I checked these:
blkid says to both hdds: PTUUID=".....hjhkkfhsdk....." PTTYPE="gpt"
lsblk says nothing on neither drives, TYPE: disk
mdadm --assemble /dev/md0 /dev/sdc1 /dec/sdd1mdadm: cannot open device /dev/sdc1: No such file or directory
mdadm: /dev/sdc1 has no superblock - assembly aborted
mdadm --run /dev/md0mdadm: error opening /dev/md0: No such file or directory
mount /md0 /mnt/Storagemount: /mnt/Storage: special device /md0 does not exist
It would be good to find a solution, because there are important data on the array. Thank you in advance!
21 Answer
I managed to get back the data. I commented out the old array in /etc/mdadm.conf, then:
created a new raid array:
mdadm --create /dev/md0 --verbose --level=1 --raid-devices=2 /dev/sdc /dev/sddsaved the layout:
mdadm --detail --scan | sudo tee -a /etc/mdadm/mdadm.confupdate-initramfs -u
mdad said: "partition table exists on /dev/sdc but will be lost or meaningless after creating array" but after mounting all the data was available on /dev/md0.
