lkml.org 
[lkml]   [2010]   [Feb]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: Linux mdadm superblock question.
From
On Sat, Feb 13, 2010 at 11:21 PM,  <david@lang.hm> wrote:
> On Sat, 13 Feb 2010, Michael Evans wrote:
>
>> On Sat, Feb 13, 2010 at 5:51 PM, Volker Armin Hemmann
>> <volkerarmin@googlemail.com> wrote:
>>>>
>>>> 0.90 has a very bad problem, which is that it is hard to distinguish
>>>> between a RAID partition at the end of volume and a full RAID device.
>>>> This is because 0.90 doesn't actually tell you the start of the device.
>>>>
>>>> Then, of course, there are a lot of limitations on size, number of
>>>> devices, and so on in 0.90.
>>>
>>> but it is the only format supporting autodetection.
>>>
>>> So - when will autodetection be introduced with 1.X? And if not, why not?
>>>
>>> All I found was 'autodetection might be troublesome' and nothing else.
>>>  But dealing with initrds is troublesome too. Pure evil even.
>>>
>>> Gl?ck Auf,
>>> Volker
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>>
>>
>> I remember hearing that 1.x had /no/ plans for kernel level
>> auto-detection ever.  That can be accomplished in early-userspace
>> leaving the code in the kernel much less complex, and therefore far
>> more reliable.
>>
>> In other words, 'auto-detection' for 1.x format devices is using an
>> initrd/initramfs.
>
> hmm, I've used 1.x formats without an initrd/initramfs (and without any
> conifg file on the server) and have had no problem with them being
> discovered. I haven't tried to use one for a boot/root device, so that may
> be the difference.
>
> David Lang

Yes, that is the difference. You must have a more traditional simple
block device and filesystem drivers compiled in. You have no need for
extra drivers or higher level device detection and evaluation (with
user-set policies to determine operation). Anything past root-fs
mount can happen in normal user-space before logins are enabled.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2010-02-14 09:41    [W:0.125 / U:2.620 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site