Re: On the subject of RAID-6 corruption recovery

["H. Peter Anvin" <hpa@zytor.com>]

Mattias Wadenstein wrote:
> On Mon, 7 Jan 2008, Thiemo Nagel wrote:
> 
>>> What you call "pathologic" cases when it comes to real-world data are 
>>> very common.  It is not at all unusual to find sectors filled with 
>>> only a constant (usually zero, but not always), in which case your 
>>> **512 becomes **1.
>>
>> Of course it would be easy to check how many of the 512 Bytes are 
>> really different on a case-by-case basis and correct the exponent 
>> accordingly, and only perform the recovery when the corrected 
>> probability of introducing an error is sufficiently low.
> 
> What is the alternative to recovery, really? Just erroring out and 
> letting the admin deal with it, or blindly assume that the parity is wrong?
> 

Erroring out.  Only thing to do at that point.

	-hpa