On 25/01/2024 at 02:57, Roger Heflin wrote:
dd if=/dev/zero of=/dev/sdb bs=512 count=1 (for each disk).
I'm afraid it won't help.
As far as I can see, having an MBR signature in the first sector does
not prevent blkid or mdadm from detecting the RAID superblock.
Also, previous mail from the OP show that the disks have GPT partition
tables (as expected with 3 TiB) which usually span (~16 KiB) beyond the
beginning of the 1.2 RAID superblock (4 KiB) so I suspect that the RAID
superblock was overwritten.
A tiny hope is that the RAID member was actually in a partition but the
geometry in the partition table is wrong or the kernel does not read it
properly (I have seen this once). You can check the partition table and
how the kernel sees the partition with
fdisk -l /dev/sdb
cat /sys/block/sdb/sdb1/start
cat /sys/block/sdb/sdb1/size
On Wed, Jan 24, 2024 at 7:13 PM RJ Marquette <rjm1@xxxxxxxxx> wrote:
It looks like this is what happened after all. I searched for "MBR Magic aa55" and found someone else with the same issue long ago: https://serverfault.com/questions/580761/is-mdadm-raid-toast Looks like his was caused by a RAID configuration option in BIOS. I recall seeing that on mine; I must have activated it by accident when setting the boot drive or something.
I swapped the old motherboard back in, no improvement, so I'm back to the new one. I'm now running testdisk to see if I can repair the partition table.
