bin/166589: atacontrol(8) incorrectly treats RAID10 and 0+1 the same

[Alexander Motin]

The following reply was made to PR bin/166589; it has been noted by GNATS.

From: Alexander Motin <mav at FreeBSD.org>
To: Allen Landsidel <landsidel.allen at gmail.com>
Cc: bug-followup at FreeBSD.org
Subject: Re: bin/166589: atacontrol(8) incorrectly treats RAID10 and 0+1 the
 same
Date: Tue, 15 Jan 2013 18:35:43 +0200

 Please, be my guest to show me where atacontrol(8) controls any hardware
 RAID controller, or anything except ataraid(4) at all.
 
 On 15.01.2013 18:26, Allen Landsidel wrote:
 > The PR is about hardware raid controllers and their interface with
 > atacontrol, not ataraid.
 > 
 > On 1/15/2013 11:25, Alexander Motin wrote:
 >> At what point have we talked about hardware RAID controllers? ataraid(8)
 >> never controller hardware RAID controllers, but only Soft-/Fake-RAIDs
 >> implemented by board BIOS'es during boot and OS drivers after that.
 >>
 >> On 15.01.2013 18:22, Allen Landsidel wrote:
 >>> Your solution then is to require everyone use software raid on their
 >>> hardware raid controllers?
 >>>
 >>> On 1/15/2013 11:20, Alexander Motin wrote:
 >>>> On 15.01.2013 18:03, Allen Landsidel wrote:
 >>>>> I'm also extremely interested to hear how you intend to "handle it as
 >>>>> RAID10 at the OS level" since that is, in fact, impossible.
 >>>> Easily!
 >>>>
 >>>>> If it's a RAID0+1 in the controller, than it's a RAID0+1. Period.  The
 >>>>> OS can't do anything about it.  A single disk failure is still
 >>>>> knocking
 >>>>> half the array offline (the entire failed RAID-0) and you are left
 >>>>> with
 >>>>> a functioning RAID-0 with no redundancy at all.
 >>>> ataraid(8) in question (and its new alternative graid(8)) controls
 >>>> software RAIDs. It means that I can do anything I want in software as
 >>>> long as it fits into existing on-disk metadata format. If RAID BIOS
 >>>> wants to believe that two failed disks of four always mean failed array
 >>>> -- it is their decision I can't change. But after OS booted nothing
 >>>> will
 >>>> prevent me from accessing still available data replicas.
 >>>>
 >>>>> On
 >>
 > 
 
 
 -- 
 Alexander Motin