Re: Spares not added upon reboot after distro upgrade

[Jan Ceuleers <jan.ceuleers@computer.org>]

On 08/22/2012 01:26 PM, Jan Ceuleers wrote:
> On 08/19/2012 09:42 AM, Jan Ceuleers wrote:
> ...
> 
>> For the first time ever I tried mdadm's incremental mode. So before
>> issuing the above two commands I tried the following;
>>
>> root@zotac:~# mdadm -I /dev/sde2
>> mdadm: failed to add /dev/sde2 to /dev/md0: Invalid argument.
> 
> I have now straced this, and here are the offending lines:
> 
> ioctl(4, 0x40140921, 0x7fff4bda3858)    = -1 EINVAL (Invalid argument)
> write(2, "mdadm: failed to add /dev/sde2 t"..., 62mdadm: failed to add
> /dev/sde2 to /dev/md0: Invalid argument.
> 
> fd 4 is /dev/md0
> 
> How does one decode the ioctl call?

Seems to be ADD_NEW_DISK(MD_MAJOR=md0, &mdu_disk_info_t)

I'm afraid I don't know how to interpret the last argument: is this a
pointer or is it the contents of the struct (which should contain five
ints, namely number, major, minor, raid_disks and state)?