Re: regression: drive was detected as raid member due to metadata on partition

["Sven Köhler" <sven.koehler@gmail.com>]

Am 18.04.24 um 09:31 schrieb Li Nan:
> 
> 
> 在 2024/4/14 5:37, Sven Köhler 写道:
> 
> [...]
> 
>>>
>>> I used your command and config, updated kernel and mdadm, but raid also
>>> created correctly after reboot.
>>>
>>> My OS is fedora, it may have been affected by some other system tools? I
>>> have no idea.
>>
>> The Arch kernel has RAID autodetection enabled. I just tried to 
>> reproduce it. While mdadm will not consider /dev/sd[ab] as members, 
>> the kernel's autodetection will. For that you have to reboot.
>>
> 
> It is not about autodetection. Autodetection only deals with the devices in
> list 'all_detected_devices', device is added to it by blk_add_partition().
> So sdx will not be added to this list, and will not be autodetect.

I apologize. It's not the kernel autodetection. Arch Linux is using udev 
rules to re-assemble mdadm array during boot. The udev rules execute

   /usr/bin/mdadm -If $name

where $name is likely a device like /dev/sda. I'm not sure yet whether 
the udev rules have changed or mdadm has changed.

I will continue digging.