Re: Find mismatch in data blocks during raid6 repair

Hello John,

On Thursday, June 21, 2012 01:38:38 PM John Robinson wrote:

On 20/06/2012 18:41, Robert Buchholz wrote:
[...]

quoted

When repairing a full raid6 with no missing drives
(raid-devices=n+2), a single inconsistent data block could be
detected

Yes, it could. See Neil Brown's blog post as to the many reasons why
this isn't implemented: http://neil.brown.name/blog/20100211050355

Thank you for the pointer, I did not find the article before.
I agree with Neil's premise, this should not be run on a mounted raid as 
changing data blocks can be a problem, and it should not be the default 
for resync. However, as both Neil and commenters point out, this is a 
valuable (offline) repair option.

Do you know whether the "smart" algorithm or the API necessary to 
construct a user space program are on the agenda?


Cheers

Robert