Re: journal disk become the first of --detail list after fail/remove one disk

[Guoqing Jiang <gqjiang@suse.com>]

On 08/04/2016 07:34 AM, Adam Goryachev wrote:
>
>
> On 4/08/2016 20:52, Yi Zhang wrote:
>> # mdadm -D /dev/md0
>> /dev/md0:
>>          Version : 1.2
>>    Creation Time : Thu Aug  4 18:42:19 2016
>>       Raid Level : raid4
>>       Array Size : 3139584 (2.99 GiB 3.21 GB)
>>    Used Dev Size : 523264 (511.00 MiB 535.82 MB)
>>     Raid Devices : 7
>>    Total Devices : 7
>>      Persistence : Superblock is persistent
>>
>>    Intent Bitmap : Internal
>>
>>      Update Time : Thu Aug  4 18:43:22 2016
>>            State : clean, degraded
>>   Active Devices : 6
>> Working Devices : 7
>>   Failed Devices : 0
>>    Spare Devices : 1
>>
>>       Chunk Size : 512K
>>
>>             Name : dhcp-12-125.nay.redhat.com:0  (local to host 
>> dhcp-12-125.nay.redhat.com)
>>             UUID : 29a267c2:04e91998:639e6eef:64ddbab0
>>           Events : 23
>>
>>      Number   Major   Minor   RaidDevice State
>>         7       7        0        -      journal   /dev/loop0
>>         1       7        2        1      active sync /dev/loop2
>>         2       7        3        2      active sync /dev/loop3
>>         3       7        4        3      active sync /dev/loop4
>>         4       7        5        4      active sync /dev/loop5
>>         5       7        6        5      active sync /dev/loop6
>>         8       7        7        6      active sync /dev/loop7
>>
>
> I'm not really sure about the journal/your report, but also why does 
> the above show 1 spare device? I would expect spare should mean that 
> there is a device available to take over automatically if one of the 
> active devices becomes faulty, but that doesn't seem to be the case. 
> Should a journal device be counted as Active & Working (or faulty) 
> instead of Spare?

Agree,  or maybe "Journal Devices" can be added for it (but both kernel 
and mdadm need to modify md_u.h I think).

Regards,
Guoqing