On Wed, 24 Mar 2021 14:44:07 +0000 Andy Smith <andy@xxxxxxxxxxxxxx> wrote: > The default metadata version (1.2) is placed at the start of an > array, so even if zeroed this will prevent the array member being > used as the filesystem that is on top of it. > ... > Finally, if you are on superblock versions 1.1 or 1.2 you may be > able to work out the offset into the device and use a loop device to > skip that, so treating it as a normal filesystem: > > https://raid.wiki.kernel.org/index.php/RAID_superblock_formats#The_version-1_Superblock_Format Also could delete the partition and recreate it with the new starting offset, matching the offset for actual data. Recently I've migrated a couple of disks off LVM in this manner. Or if the entire disk was used as an array member, then create a brand new partition table on it, with a single partition of the required offset. sfdisk is helpful for dumping partitions into a text file ("-d"), which can then be edited and restored to the device with "sfdisk /dev/disk < file". All of this is likely more complex if you have to use GPT. -- With respect, Roman
