On Wed, 5 Jan 2011 18:03:47 -0600
"Leslie Rhorer" [off-list ref] wrote:

quoted

	RAID1 certainly offers the most robust solution, especially
with more than 1 mirror.

quoted

	RAID1 is as safe as it gets

Are you sure about that?

	Well, yeah.

Considering that mdadm's handling of corrupt data
on
RAID1 devices is pretty simplistic (obviously it does not have per-block
checksums anywhere, it does not do 'voting' on RAID1 with more than 2
devices), it basically has no way of knowing if a block of data is
returned

	Well I can't answer to that very well.  Some of the other folks who
are more familiar with the mechanics of the situation will have to comment,
but each single member of a RAID1 array holds the entire contents of the
data set.  A 3N has 3 complete sets of data on it, and piecing together a
fragmented data set from 3 complete sets of data is going to be more likely
to produce an intact data set than from 1 + 1/N data sets.

differently by some of the component devices, which one has the 'correct'
data. From what I understand, RAID5 and especially RAID6 give a much
better
protection in this situation.

	It's certainly not been my experience.  That said, I do run RAID6
arrays, along with RAID1 arrays.  YMMV, of course.