grub-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH] nested partitions


From: Vladimir 'phcoder' Serbinenko
Subject: Re: [PATCH] nested partitions
Date: Tue, 25 Aug 2009 22:14:45 +0200

On Robert's request I write about the usage cases I'm aware. It's by
no means complete

1) bsdlabel on PC-style. By most *BSD flavours
2) sunpc on PC-style. By Solaris
3) Some kind on PC-style on PC-style by Minix. (not sure about this
one -it was a long time ago)
I vaguely heard of (I may be completely wrong):
4) amiga on PC-style by AROS
5) sun on apple. Polaris (?)

On Mon, Aug 24, 2009 at 3:39 PM, Vladimir 'phcoder'
Serbinenko<address@hidden> wrote:
> Rediff
>
> On Mon, Aug 24, 2009 at 12:57 AM, Vladimir 'phcoder'
> Serbinenko<address@hidden> wrote:
>> Rediff
>> On Mon, Aug 17, 2009 at 4:34 PM, Vladimir 'phcoder'
>> Serbinenko<address@hidden> wrote:
>>> On Mon, Aug 17, 2009 at 4:06 PM, Robert Millan<address@hidden> wrote:
>>>> On Mon, Aug 17, 2009 at 03:00:52PM +0200, Vladimir 'phcoder' Serbinenko 
>>>> wrote:
>>>>> Rediff and few fixes
>>>>
>>>> Please note that after what we discussed on IRC, we need to find a solution
>>>> that wouldn't make boot time increase linearly with the number of 
>>>> filesystems
>>>> or partmaps GRUB supports.
>>>>
>>> It probe time scales linearly no matter what we do. Fortunately with
>>> disk cache few first sectors are read and checked for different
>>> signatures which is fast. As for module autoload with search patch it
>>> doesn't happen except in the failure to access requested device.
>>>> I really think supporting every sort of combination is too extreme.  For
>>>> example who would want an msdos/msdos chain?  OpenSolaris creates one, but
>>>> it's a false positive.
>>>>
>>> minix does it and it's not a false positive.
>>>> The overall idea *is* nice.  Some combinations (e.g. msdos/bsd) are cleaner
>>>> this way, but supporting everything doesn't scale well.
>>> AFAIK no partmap goes beyond first 16K for signature checking. Time
>>> for signature checking can be neglected and 16K would be read for
>>> filesystem probe too. Additionally e.g. (hd0,1) is probed for
>>> subpartitions only if (hd0,1,X) is requested or we're scanning through
>>> partitions. In last case we're likely to fsprobe partition anyway so
>>> it doesn't create any overhead
>>>>
>>>> Perhaps we can explicitly list which combinations make sense?  So when an
>>>> msdos label is found, its partitions are probed for bsd labels too, but not
>>>> for msdos labels again, etc.
>>>>
>>>> --
>>>> Robert Millan
>>>>
>>>>  The DRM opt-in fallacy: "Your data belongs to us. We will decide when (and
>>>>  how) you may access your data; but nobody's threatening your freedom: we
>>>>  still allow you to remove your data and not access it at all."
>>>>
>>>>
>>>> _______________________________________________
>>>> Grub-devel mailing list
>>>> address@hidden
>>>> http://lists.gnu.org/mailman/listinfo/grub-devel
>>>>
>>>
>>>
>>>
>>> --
>>> Regards
>>> Vladimir 'phcoder' Serbinenko
>>>
>>> Personal git repository: http://repo.or.cz/w/grub2/phcoder.git
>>>
>>
>>
>>
>> --
>> Regards
>> Vladimir 'phcoder' Serbinenko
>>
>> Personal git repository: http://repo.or.cz/w/grub2/phcoder.git
>>
>
>
>
> --
> Regards
> Vladimir 'phcoder' Serbinenko
>
> Personal git repository: http://repo.or.cz/w/grub2/phcoder.git
>



-- 
Regards
Vladimir 'phcoder' Serbinenko

Personal git repository: http://repo.or.cz/w/grub2/phcoder.git




reply via email to

[Prev in Thread] Current Thread [Next in Thread]