Linux mdadm has some quirks, one of them is building raid10 with only two disks. There are some reports that it's way faster (twice, both in read and write) as RAID1:
- https://raid.wiki.kernel.org/index.php/Performance
- https://web.archive.org/web/20160314063744/http://blog.a2o.si/2014/09/07/linux-software-raid-why-you-should-always-use-raid-10-instead-of-raid-1/
(raid1 vs raid10f2)
Is the raid10 on two disks as secure as raid1? What are the dangers of using such solution instead of "proper" raid1?
Best Answer
Well, as the second link you provide suggests there's no certainty that mirrored stripes are on separate disks - so to be honest the concept is worthless and dangerous.