In article <20060610190920.35138325C7@cs.usask.ca>,
	Greg Oster <oster@cs.usask.ca> writes:
> Mark Cullen writes:
>> Greg Oster wrote:
>> > Mark Cullen writes:
>> > 
>> >>but the data on the two disks is still 
>> >>different, that is, /dev/wd3a still has the old copy of the data. 
>> > 
>> > 
>> > Um... after the 'raidctl -i raid0' completes, the data parts of wd1a 
>> > and wd3a had better be *exactly* the same!
>> 
>> They weren't the same afterwards! If I mounted just the disk that was 
>> missing when I added the new data, after doing an -i, the data was *not* 
>> there on that disk. I had to force a rebuild of the disk in order to get 
>> the data on to it.
>>
>> However, I may know why? I took wd1 out, and put the new data on wd3. If 
>> I issue a -i, does it use the first disk in the array config to rebuild 
>> the parity? 
> 
> Yes.  The first disk in a RAID 1 set is considered the 'master', and 
> in the face of having 2 disks where it can't tell which is "more 
> correct", the 'master' will be used as the difinitive source.

Now, if Mark had just removed wd1, wrote some data to wd3,
shutdown cleanly and added wd1 back, wd3 would become the
master, right?  We hope?  It only happened the way it did
because he used "raidctl -C"?


Frederick