GRUB2 for Debian 8 in an i586

[Narcis Garcia]

Hello,

I've tried many combinations of a fresh Debian 8 installation on a
computer with «Intel Pentium MMX» at 200MHz processor.

Debian CD boots and DebianInstaller performs all processes without any
problem, including the GRUB bootloader install (all cases at /dev/sda)

GRUB only boots installed system when there is only a sigle partition
for everything. GRUB fails to read on boot any filesystem if there are
two partitions.

CASE 1: Single drive
/dev/sda1 primary for all space (32GiB) Ext4 mounted on /
Succeeds: boots operating system.

CASE 2: Single drive
/dev/sda1 primary for 1GB Ext4 mounted on /boot
/dev/sda2 primary for 10GB Ext4 mounted on /
error: unknown filesystem.
Entering rescue mode...
grub rescue> ls
(hd0) (hd0,msdos1) (hd0,msdos2) (fd0)
grub rescue> ls (hd0,msdos1)/
(hd0,msdos1): Filesystem is unknown.

CASE 3: Three hard disks
/dev/sda1 primary for 10GB Ext4 mounted on /
/dev/sdb blank
/dev/sdc blank
Succeeds: boots operating system.

CASE 4: Three hard disks
/dev/sda1 primary for 1GB Ext4 mounted on /boot
/dev/sda2 primary for 10GB Ext4 mounted on /
/dev/sdb blank
/dev/sdc blank
error: unknown filesystem.
Entering rescue mode...
grub rescue> ls
(hd0) (hd0,msdos1) (hd0,msdos2) (hd1) (hd2) (fd0)
grub rescue> ls (hd0,msdos1)/
(hd0,msdos1): Filesystem is unknown.

CASE 5: Three hard disks
/dev/sda1 primary for all space (32GiB) volume for RAID
/dev/sdb1 primary for all space (32GiB) volume for RAID
/dev/sdc1 primary for all space (32GiB) volume for RAID
/dev/md0 for all space (100GB) Ext4 mounted on /
error: disk `mduuid/a867853f5e9773488fa4911285e2db93´ not found.
Entering rescue mode...
grub rescue> ls
(hd0) (hd0,msdos1) (hd1) (hd1,msdos1) (hd2) (hd2,msdos1) (fd0)
grub rescue> ls (hd0,msdos1)/
(hd0,msdos1): Filesystem is unknown.

CASE 6: Three hard disks
/dev/sda1 primary for 1GiB Ext 4 mounted on /boot
/dev/sda2 primary for 31GiB volume for RAID
/dev/sdb1 primary for 1GiB unused
/dev/sdb2 primary for 31GiB volume for RAID
/dev/sdc1 primary for 1GiB unused
/dev/sdc2 primary for 31GiB volume for RAID
/dev/md0 for all RAID space (~100GB) Ext4 mounted on /
error: unknown filesystem.
error: disk `mduuid/a867853f5e9773488fa4911285e2db93´ not found.
Entering rescue mode...
grub rescue> ls
(hd0) (hd0,msdos1) (hd0,msdos2) (hd1) (hd1,msdos1) (hd1,msdos2) (hd2)
(hd2,msdos1) (hd2,msdos2) (fd0)
grub rescue> ls (hd0,msdos1)/
(hd0,msdos1): Filesystem is unknown.

OTHER CASES:
- Tried with Ext3 filesystem with same results.
- Tried a Live-boot to chroot and perform "update-grub" + "grub-install
/dev/sda". Commands succeeded with no errors.
- Filesystem & contents are consistent in all cases.