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

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

Hi,

Am 11.04.24 um 04:25 schrieb Li Nan:
> Hi,
>
> 在 2024/4/11 4:59, Sven Köhler 写道:
>> Hi,
>>
>> Am 10.04.24 um 03:56 schrieb Li Nan:
>>> Hi, Köhler
>>>
>>> 在 2024/4/9 7:31, Sven Köhler 写道:
>
> [...]
>
>>
>> I should have mentioned the mdadm and kernel version. I am using 
>> mdadm 4.3-2 and linux-lts 6.6.23-1 on Arch Linux.
>>
>> I created the array very similar to what you did:
>> mdadm --create /dev/md4 --level=6 --raid-devices=4 --metadata=0.90 
>> /dev/sd[abcd]4
>>
>> My mdadm.conf looks like this:
>> DEVICE partitions
>> ARRAY /dev/md/4 metadata=0.90  UUID=...
>>
>> And /proc/partitions looks like this:
>>
>> major minor  #blocks  name
>>     8        0 2930266584 sda
>>     8        1    1048576 sda1
>>     8        2   33554432 sda2
>>     8        3   10485760 sda3
>>     8        4 2885176775 sda4
>>     8       16 2930266584 sdb
>>     8       17    1048576 sdb1
>>     8       18   33554432 sdb2
>>     8       19   10485760 sdb3
>>     8       20 2885176775 sdb4
>>     8       32 2930266584 sdc
>>     8       33    1048576 sdc1
>>     8       34   33554432 sdc2
>>     8       35   10485760 sdc3
>>     8       36 2885176775 sdc4
>>     8       48 2930266584 sdd
>>     8       49    1048576 sdd1
>>     8       50   33554432 sdd2
>>     8       51   10485760 sdd3
>>     8       52 2885176775 sdd4
>>
>>
>> Interestingly, sda, sdb, etc. are included. So "DEVICE partitions" 
>> actually considers them.
>>
>
> 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.

I used this ISO in a VM with 2 harddisks to reproduce the issue: 
https://mirror.informatik.tu-freiberg.de/arch/iso/2024.04.01/archlinux-2024.04.01-x86_64.iso


Kind Regards,
   Sven