Re: RAID 1 resync with both members good.

[Luca Berra <bluca@comedia.it>]

On Fri, May 08, 2009 at 10:32:01AM +1000, NeilBrown wrote:
>On Thu, May 7, 2009 6:08 pm, Simon Jackson wrote:
>> Could someone help me understand why I am seeing the following
>> behaviour?
>>
>> We use a pair of disks with 3 RAID1 partitions inside an appliance
>> system.
>>
>> During testing we have seen some instances of the RAID devices resyncing
>> even though both members are marked as good in the output of
>> /proc/mdstat.
>
>That is exactly as expectedc.
>If one of the devices had failed and was being replaced by a spare, you
>would see "recovery" not "resync".
>
>Resync happens after an unclean shutdown.
>In that case, both drives have good data, but they might not be the same.
>The resync makes sure that all copies have exactly the same data.
>
>So you there must have been an unclean shutdown before the most recent
>restart.

or a stupid udev rule that gets incremental assembly wrong

L.

-- 
Luca Berra -- bluca@comedia.it
         Communication Media & Services S.r.l.
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