mdadm ignores "--force" switch on Intel Fake Raid

[Anatoly Zapadinsky]

I have an old system that is supplied with an Intel Option ROM that does not support > 2tb hard drives. Linux works perfectly on this system and see hard drives bigger than 2tb though. I want to create a raid with imsm metadata format and attach it to another system later. mdadm dosn't let me do this. I try to force raid creating using the "--force" option but it is ignored.

#mdadm --version
mdadm - v3.3 - 3rd September 2013

#mdadm --create --verbose /dev/md/imsm --level=5 --raid-devices=3 /dev/sd[b-d] --metadata=imsm --force
mdmon: Cannot create this array on device /dev/sdb
mdadm: /dev/sdb is not suitable for this array.
mdmon: Cannot create this array on device /dev/sdc
mdadm: /dev/sdc is not suitable for this array.
mdmon: Cannot create this array on device /dev/sdd
mdadm: /dev/sdd is not suitable for this array.
mdadm: create aborted

It seems that it also block one from creating imsm metadata raids on AMD platform or in a virtual machine of any type. Why? Why mdadm control user? The "--force" switch is made for this. Ignore the Option ROM version and create the raid! Its a fake raid after all.

[Anatoly Zapadinsky (zapadinsky)]

Not a bug, the solution is to use IMSM_NO_PLATFORM env variable. The solution with env variable instead of a switch is odd though.