It seems the bug is that dmraid -i -r -cr /dev/sda is listing the name of the first subset rather than the superset. Your workaround won't work if you have more than one array so it seems the underlying bug will need to be fixed to have raid10 work.
** Changed in: dmraid (Ubuntu) Importance: Undecided => Medium ** Changed in: dmraid (Ubuntu) Status: New => Triaged ** Summary changed: - (fakeraid) root device not activated during boot + raid10 not activated due to array vs subarray confusion -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1202955 Title: raid10 not activated due to array vs subarray confusion To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/dmraid/+bug/1202955/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs