Bug#699434: grub-installer: support for Intel Matrix Raid

[Miquel van Smoorenburg <miquels@debian.org>]

On 02/12/13 10:59, Dmitrijs Ledkovs wrote:
> Hello Miquel,
>
> On 31 January 2013 12:40, Miquel van Smoorenburg <miquels@debian.org> wrote:
> > This is by far the most intrusive patch - all the others are trivial.
> > Description:
> >
> > - move make_device_map() upwards so that we can call it earlier
> >    in the script. Also, if $md_bootdev is set, add a (otherwise
> >    unused) "(md/0)" entry to device.map - otherwise grub-probe
> >    freaks out on upgrades.
> > - add is_mdraid_bootable(). It checks if the device is a Intel
> >    Matrix Raid device, in RAID1 mode. If not it returns false.
> >    Otherwise it sets $md_dev, $md_devs, $md_super and $md_level,
> >     and returns true.
>
>
> Why is it limited to only imsm && raid1 ?

Because it's the only thing I could test, and at the time ddf support 
was kind of wonky. So I thought it best to leave that out.

Also, only RAID1 is because I could not get grub to install on the MD 
device- it didn't accept that. And for example, grub-mkdevicemap doesn't 
create an entry for /dev/md... yet. So right now the code finds the 
devices underlying the RAID1 array and installs grub on all of them.

Someone needs to fix grub so that it understands MD devices directly. Or 
the current version might already do that, I haven't checked in a while.

> mdadm supports "imsm" superblock format levels 0,1,5,10 & "ddf"
> superblock format levels 0,1,3,4,5,1E,5E,5EE,6 with extensions of
> there off (stripped, mirrored, concatenated and spanned).
>
> Would it not be best to simply check for "imsm" || "ddf" superblock
> types? Given that mdadm supports most of the above RAID levels.

Sure.

Mike.