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Date:   Thu, 6 May 2021 12:39:42 +0200
To:     list Linux RAID <linux-raid@vger.kernel.org>
Subject: Re: raid10 redundancy
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From:   pg@mdraid.list.sabi.co.uk (Peter Grandi)
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>>> On Thu, 6 May 2021 13:09:53 +0800, d tbsky <tbskyd@gmail.com> said:

> Hi: I am curious about raid10 redundancy when created with
> disk numbers below: [...]

This looks like a "homework" question... There are a lot of
pages on the WWW that explain that in summary and detail, and
the shortest is: RAID10 only loses data if all devices that
compose one of mirror set become impaired at the same block
addresses.

More in detail I have written some posts that explain the
tradeoffs involved, they seem to be widely "misunderestimated":

https://sabi.co.uk/blog/13-one.html?130117#130117
"Comparing the resilience of RAID6 and RAID 10"

http://www.sabi.co.uk/blog/12-two.html?120218#120218
"When double parity may make some sense"