Re: Spare drive won't spin down

[Bill Davidsen <davidsen@tmr.com>]

Neil Brown wrote:
> On Fri, 7 May 2010 00:40:40 -0700 (PDT)
> Joe Bryant <tenminjoe@yahoo.com> wrote:
>
>   
>>> I'll see about fixing that.
>>>
>>> Recreate the array with "--metadata 1.0" or "--metadata 1.2" and it should work better.
>>>       
>> That's great, thanks very much.
>>
>>     
>
> It turns out it is a bit more subtle than that, though that approach may work
> for you.
> If you make an odd number of changes to the metadata, it will switch from
> doing what you want, to not.
> e.g. if /dev/foo is your spare device, then
>
>   mdadm /dev/md0 -f /dev/foo
>   mdadm /dev/md0 -r /dev/foo
>   mdadm /dev/md0 -a /dev/foo
>
> will switch between working and not working.  v0.90 metadata starts out not
> working.  v1.x start out working.
>   

So we can assume that the little dance steps above will make 1.x 
misbehave in the same way?

Could you explain (point to an explanation) why this whole odd/even 
thing exists?

-- 
Bill Davidsen <davidsen@tmr.com>
  "We can't solve today's problems by using the same thinking we
   used in creating them." - Einstein