From mboxrd@z Thu Jan  1 00:00:00 1970
From: peter@steinhoff.se
Subject: Re: Problem diagnosing rebuilding raid5 array
Date: Tue, 15 Oct 2013 11:01:07 -0400
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To: Brian Candler <b.candler@pobox.com>
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>> But has the new sdh been rebuilt completely? If that case there  
>> should be n-1 drives? Or does "spare" just means that it can be  
>> used but has no data yet?
>>
> That's what I'm not sure about. It is "clean" but it is also  
> "spare". I'm not sure what state would be seen while it is rebuilding.
>
> When the old sdh had a problem, did you mdadm /dev/mdXXX --fail /dev/sdh?
>

No, I didn't think I needed to do that. I just powered down the  
machine and took it out.

> And after you inserted the new drive, and presumably did mdadm  
> /dev/mdXXX --add /dev/sdh, did you see it start to rebuild in  
> /proc/mdstat?
>

Yes I did. It was around 20% or so when I left it.


>> Also I have my old sdh with data on it but I don't know how current  
>> that data is but perhaps I can use that somehow?
>>
> You could mdadm --examine it, but I suspect that the event count  
> will be way out of line by now.
>

I will put it in and see what it shows. Is it correct to assume that  
--examine reads the superblock and I can insert the drive into any  
machine and examine it there?

Thanks,
Peter