Re: Can I replace raid6 disk using dd?

[Ram Ramesh <rramesh2400@gmail.com>]

On 08/19/2014 04:08 AM, Ethan Wilson wrote:
> On 19/08/2014 09:09, Killian De Volder wrote:
>> No need to remove the bitmap.
>> But be very careful that the disk is exactly the same size (or bigger).
>> I recently had a disk that was slightly smaller then advertised !
>>
>> But if it's a raid6 why not just jank a disk ?
>> It's still going to be redundant, but only on 1 disk.
>>
>> Killian De Volder
>> Megasoft bvba
>> killian.de.volder@megasoft.be
>>
>
> I think it would not be accepted by MD if the size was smaller than 
> needed. At least with --replace. With the dd thing I don't know: it 
> might trust the metadata and bypass the check.... I'd be careful in 
> that case indeed.
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Thank you all. I think many feel dd is risky although doable. I felt the 
same way too. Let me look for alternate/safe ways.

I wanted to experiment because  the real data in the array is small and 
I had good backups. Still, I do not think it is worth risking the chance 
of trashing the array.  I am more worried of the what if scenario, where 
there is corruption, but not detected until my backup is no longer up to 
date - I am not fond of Murphy :-)

Ramesh