Hi there,
I'm in the process of transferring a Debian install from a single drive to
a md raid-1 /boot + md raid-1 LVM setup.
When I created the /boot array I manually assigned the device md179. Upon
rebooting the array was automatically assembled under md126.
When I run grub-install /dev/sda I get the message "Auto-detection of a
filesystem of /dev/md126 failed".
I downloaded grub2-1.99, compiled with -ggdb and eventually found that
grub-probe extracts the name field from the mdadm 1.0 raid superblock and
uses that name to determine the name of the md device. The name of the
device in my case is, according to mdadm -Q --detail, "RIPLinux:179".
So, when running "grub-probe --device /dev/md126" the program correctly
identifies the devices /dev/sd{a,b}1, retrieves the superblock from
/dev/sda1, extracts the name "RIPLinux:179" and uses the number 179 to
"incorrectly" determine that the md device is /dev/md179. It then attempts
to access /dev/md179 and fails.
The mdadm man page seems to suggest that the superblock name is arbitrary
as long as it is unique to a set of partitions that participate in an md
raid. I didn't see anything that suggests that the superblock name
necessarily has anything to do with the md device that the raid is
assembled under.
I'm pretty sure that I can get grub2 installed simply by changing the name
field in the superblock via mdadm --update. However, it seems to me that
either I am ignorant of the actual meaning of the superblock name field or
grub2 is making incorrect assumptions.
Any illumination would be appreciated.
Thanks
_______________________________________________
Help-grub mailing list
Help-grub@gnu.org
https://lists.gnu.org/mailman/listinfo/help-grub
