On Sun, Apr 18, 2010 at 10:42, Jarry <mr.ja...@gmail.com> wrote:
> On 18. 4. 2010 8:57, Ciprian Dorin, Craciun wrote:
>
>> * there is an option for the kernel that must be enabled at
>> compile time that enables automatic RAID detection and assembly by the
>> kernel before mounting /, but it works only for MD metadata 0.96 (see
>> [1]);
>> * the default metadata for `mdadm` is 1.2 (see `man mdadm`, and
>> search for `--metadata`), so when creating the RAID you must
>> explicitly select the metadata you want;
>
>> [1]
>> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=Documentation/md.txt;h=188f4768f1d58c013d962f993ae36483195fd288;hb=HEAD
>
>
> Which version of mdadm are you using? I have 3.0, and defalut metadata
> is 0.90:
>
> -e , --metadata=
> Declare the style of RAID metadata (superblock) to be used. The
> default is 0.90 for --create, and to guess for other operations.
> The default can be overridden by setting the metadata value for
> the CREATE keyword in mdadm.conf.
>
> BTW [1] says about kernel 2.6.9, things might have changed since then...
>
> Jarry
On my laptop on which I've made the experiments I have ArchLinux
(which always has the bleeding edge packages), I have 3.1.2. So maybe
between 3.0 and 3.1 there was this switch from 0.90 to 1.2 default
metadata.
About the autodetection stuff I'm absolutely positive that it only
handles 0.90 format as I've tried it and didn't work with the 1.x
version of superblock format.
Ciprian.
