Hi Brian,

--assume-clean skips over the initial resync.  Which - if you will
create a filesystem after creating the array - is a time-saving idea.
But keep in mind: even if the disks are brand new and contain only
zeros, the parity would probably look not all zeros.  So reading from
such an array would be a bad idea.
But if the next thing you do is create LVM/filesystem etc., then all bit
read from the array will have been written to before (and by that are in
sync).

Stefan

Am 06.08.2010 03:19, schrieb brian.foster@emc.com:

Hi all,

I've read in the list archives that use of --assume-clean on raid5
(raid6?) is not safe assuming the member drives are not sync, but it's
not clear to me as to why. I can see the content of an written raid5
array change if I fail a drive out of the array (created w/
--assume-clean), but data that I write prior to failing a drive remains
intact. Perhaps I'm missing something. Could somebody elaborate on the
danger/risk of using --assume-clean? Thanks in advance.

Brian
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