Re: Error during Install grub on img using loop devices

[Andrei Borzenkov]

В Sat, 27 Jun 2015 08:47:07 +0000
Divya Thaluru <address@hidden> пишет:

> >
> >> 2)I generate grub.cfg file using grub-mkconfig command. It generates
> >> grub.cfg file with loop devices as root. I have to go change manually.
> >>Is
> >> there any fix for it?
> >> 
> >
> >What do you mean "root"? Could you attach grub.cfg?
> 
> I mounted raw image as loop back device. And I am installing grub on my
> loop back device. I am installing grub with device map file. Attached
> grub.cfg file

        linux   /boot/vmlinuz-3.19.2 root=/dev/mapper/loop2p1 ro  

Well, you need to check why, condition is here:

 if [ "x${GRUB_DEVICE_UUID}" = "x" ] || [ "x${GRUB_DISABLE_LINUX_UUID}"
 = "xtrue" ] \
    || ! test -e "/dev/disk/by-uuid/${GRUB_DEVICE_UUID}" \
    || uses_abstraction "${GRUB_DEVICE}" lvm; then
  LINUX_ROOT_DEVICE=${GRUB_DEVICE}


My guess is that GRUB misdetects it as LVM. Hard to tell for old
version you are using. It does not happen in master:

address@hidden:~/build/grub> LC_ALL=C df -h /mnt
Filesystem           Size  Used Avail Use% Mounted on
/dev/mapper/loop0p2  9.0M  5.5M  3.6M  61% /mnt
address@hidden:~/build/grub> sudo pkgdatadir=$PWD ./grub-probe -t abstraction 
/mnt
address@hidden:~/build/grub> 


> >
> >> 3)If I add verbose option to grub-install, grub-install command won’t
> >>work
> >> and it just displays version info as output. Is there any patch for
> >>this
> >> fix?
> >> 
> >
> >Copy'n'paste would be good. But grub-install did not really support
> >--verbose as far as I remember; it was --debug.
> 
> 
> bash-4.3# grub-install -v --no-floppy --grub-mkdevicemap=/device.map
> /dev/loop2
> grub-install (GRUB) 2.00

Well, there was some non-backward compatible changes indeed since 2.00
(unintentional). In 2.02~beta2 it should indeed bump verbosity, in
2.00 it did display version

     print_option_help "-v, --version" "$(gettext "print the version
     information and exit")"


> bash-4.3# grub-install --no-floppy --grub-mkdevicemap=/device.map
> /dev/loop2
> device-mapper: table ioctl on  failed: No such device or address
> …..
> Installation finished. No error reported.
> 
> In first try, it did not install grub but in second case it installed grub.
> 
> 
> 
> 
> >
> >> 4)At the time of boot, I am getting a following error message
> >> error: no symbol table
> >> 
> >> Loading Linux 3.19.2…. ...
> >> Press any key to continue ...
> >> 
> >> The system then proceeds to boot normally.
> >> 
> >> 
> >
> >Do you boot on real hardware or QEMU (or similar) using just installed
> >image?
> 
> These seems to be fixed if I don’t strip symbols from grub binaries.
> 

How did you manage it? Do *NOT* ever mess with grub Makefiles for
targets - it is absolutely and utterly unsupported. GRUB already strips
everything that is not needed.