Hi,

After the grub2 update today (jessie), I noticed some noises in
dmesg's output, as pasted below:
-------------------------------------------------------------
[ 5540.810075] EXT4-fs (sda1): VFS: Can't find ext4 filesystem
[ 5540.811496] EXT4-fs (sda1): VFS: Can't find ext4 filesystem
[ 5540.812881] EXT4-fs (sda1): VFS: Can't find ext4 filesystem
[ 5540.817271] XFS (sda1): Invalid superblock magic number
[ 5540.829814] FAT-fs (sda1): utf8 is not a recommended IO charset for
FAT filesystems, filesystem will be case sensitive!
[ 5540.829943] FAT-fs (sda1): invalid media value (0x7d)
[ 5540.829946] FAT-fs (sda1): Can't find a valid FAT filesystem
[ 5540.831185] FAT-fs (sda1): utf8 is not a recommended IO charset for
FAT filesystems, filesystem will be case sensitive!
[ 5540.831268] FAT-fs (sda1): invalid media value (0x7d)
[ 5540.831271] FAT-fs (sda1): Can't find a valid FAT filesystem
[ 5540.835528] VFS: Can't find a Minix filesystem V1 | V2 | V3 on device
sda1.
[ 5540.837038] hfsplus: unable to find HFS+ superblock
[ 5540.838378] qnx4: no qnx4 filesystem (no root dir).
[ 5540.839506] You didn't specify the type of your ufs filesystem

mount -t ufs -o ufstype=sun|sunx86|44bsd|ufs2|5xbsd|old|hp|nextstep|
nextstep-cd|openstep ...
ufstype=old
[ 5540.839698] ufs_read_super: bad magic number
[ 5540.842699] hfs: can't find a HFS filesystem on dev sda1
[ 5545.960192] EXT4-fs (sdb2): mounted filesystem with ordered data
mode. Opts: (null)
------------------------------------------------------------------
This is odd, as this would not happen in previous version of grub2
 (according to my fuzzy memory)

You can see some programs tried to detect the type of my /dev/sda1,
and the fact is, my
/dev/sda uses GPT partition, while my machine has no EFI/UEFI and
has just BIOS, then /dev/sda1 is a "bios_grub" part[1].

I think update-grub2 (and programs it invoked) can do more elegant,
on issue like this.

Thanks :)


[1] see doc of GRUB2. Or I have to add --force option when using
    grub-install, in order to boot from GPT-partitioned disk on a BIOS
    PC.

Control: reassign -1 os-prober
[...]

This is all done by os-prober, not by update-grub itself.  (But it
should be entirely cosmetic.)

Dear Maintainer,

*** Reporter, please consider answering these questions, where appropriate ***

I'm still seeing this problem and would hope that os-prober would handle
bios_grub partitions more intelligently (with maybe an option to try
detecting a filesystem on a bios_grub partition).

*** End of the template - remove these template lines ***