On 15/07/2020 00:27, Roger Heflin wrote:
Did you create the partition before you added the disk to mdadm or after? If after was it a dos or a gpt? Dos should have only cleared the first 512byte block. If gpt it will have written to the first block and to at least 1 more location on the disk, possibly causing data loss. If before then you at least need to get rid of the partition table completely. Having a partition on a device will often cause a number of things to ignore the whole disk. I have debugged "lost" pv's where the partition effectively "blocked" lvm from even looking at the entire device that the pv was one.
If an explicit assemble works, then if you can get hold of a temporary spare/loan disk, I'd slowly move the new disks across to partitions by doing a --replace, not a --remove / --add. A replace will both keep the array protected against failure, and also not stress the array because it will just copy the old disk to the new, rather than rebuilding the new disk from all the others.
I'm not sure about the commands, but iirc mdadm has a --wipe-superblock command or something, as does fdisk have something to wipe a gpt, so make sure you clear that stuff out before re-initialising a disk.
Cheers, Wol
