[systemd-devel] How to factory reset?

[Chris Murphy]

On Wed, Mar 11, 2015 at 1:46 PM, Kay Sievers <kay at vrfy.org> wrote:
> On Wed, Mar 11, 2015 at 7:45 PM, Chris Murphy <lists at colorremedies.com> wrote:
>> On Wed, Mar 11, 2015 at 11:50 AM, Kay Sievers <kay at vrfy.org> wrote:
>>
>>>There is no
>>> point in handling raid without native firmware support; manual
>>> intervention is needed anyway on these systems if things go wrong, and
>>> that step can just re-create the ESP content if needed.
>>
>> I don't agree with this. OS X supports this for 10+ years on EFI with
>> software raid, and no such thing as firmware raid.
>
> It is the Apple firmware and not OS X. The firmware supports all sorts
> of Apple specific things like HFS+ and drivers for the WiFi hardware.
> And that is exactly what I meant with native support. :)

Apple's raid support is not enabled by Apple firmware. That Apple's
firmware understands HFS+ is completely beside the point. They could
put their bootloader on the ESP, it's the bootloader that understands
Apple raid, finds and loads the kernel. The reason the firmware has
HFS+ support baked in is the HFS+ volume header contains a hint for
the active system, rather than depending on NVRAM.

Back on Linux though, any dependency on proprietary firmware raid,
means Btrfs raid cannot be used at all on those drives so I don't see
how this is a general purpose solution. BIOS permits a superior
solution.


-- 
Chris Murphy