> That command wouldn't have the effect you describe (and is visible in > the --examine output - thanks). > > Maybe you mean "--add" ??? I feel like I did `--assemble` but it is entirely possible I am not remembering correctly and did an `--add`. It may be worth testing both scenarios to see if `mdadm` could stop people like me from shooting themselves in the foot. To be clear I am not placing any blame on `mdadm` for my stupid mistakes. > To reconstruct the correct metadata, the easiest approach is probably to > copy the superblock from the best drive in md0 and use a binary-editor > to change the 'Device Role' field to an appropriate number for each > different device. Maybe your kernel logs will have enough info to > confirm which device was in each role. I checked all my logs and all I can see is the start of the reshape with no indication of what is changing. Jan 14 00:20:46 nas2 kernel: md: reshape of RAID array md0 > One approach to copying the metadata is to use "mdadm --dump=/tmp/md0 /dev/md0" > which should create sparse files in /tmp/md0 with the metadata from each > device. > Then binary-edit those files, and rename them. Then use > mdadm --restore=/tmp/md0 /dev/md0 > to copy the metadata back. Maybe. > > Then use "mdadm --examine --super=1.2" to check that the superblock > looks OK and to find out what the "expected" checksum is. Then edit the > superblock again to set the checksum. > > Then try assembling the array with > mdadm --assemble --freeze-reshape --readonly .... > > which should minimize the damage that can be done if something isn't > right. > Then try "fsck -n" the filesystem to see if it looks OK. Since I do not know the disk order I'll work up a script to use overlays and craft these super blocks in each permutation with `fsck` checks to see which one gets me the most data back. I truly appreciate the help, thank you very much. I'll let you all know how it goes :)
