On 2017-05-06 NeilBrown wrote:
On Mon, May 01 2017, Adam Thompson wrote:
The problem is that the disks use the v0.90 metadata format, and they came from a big-endian system, not a little-endian system. MD superblocks *since* v0.90 are endian-agnostic, but back in v0.90, the superblock was byte-order specific.
Look for "--update=byteorder" in the mdadm man page.
Doh! Make that double-doh! So easy, yet so hidden. I'll request one little tweak/feature: can the man page be updated so that that option has the word "endian" somewhere in its description? I think most of us did as the first attempt at helping: man mdadm, search endian. When that failed, no one thought to search byteorder! Even google didn't fix that one, at least not for my web searches.
Thanks linux-RAID guys (especially Neil), once again you make the difficult easy.