Re: Aw: Re: grub search - reboot ?

[Andrei Borzenkov]

14.09.2016 12:41, address@hidden пишет:
>> Why do you think it is related to this command? Add some delay and debug
>> print to make sure where exactly it reboots.
> 
> this is the entry from grub.conf
> 
> menuentry 'CentOS Linux (3.10.0-327.el7.x86_64) 7 (Core)' --class centos 
> --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 
> 'gnulinux-3.10.0-327.el7.x86_64-advanced-e6d48e3e-10ba-415b-91d0-87a0bb295a60'
>  {
>               load_video
>               set gfxpayload=keep
>               insmod gzio
>               insmod part_msdos
>               insmod xfs
>               set root='hd0,msdos1'
> #             if [ x$feature_platform_search_hint = xy ]; then
> #               search --no-floppy --fs-uuid --set=root --hint='hd0,msdos1'  
> 68c4b337-a6a6-4045-9b6d-750de44610f6
> #             else
> #               search --no-floppy --fs-uuid --set=root 
> 68c4b337-a6a6-4045-9b6d-750de44610f6
> #             fi
>               linux16 /vmlinuz-3.10.0-327.el7.x86_64 
> root=/dev/mapper/centos-root ro crashkernel=auto rd.lvm.lv=centos/root 
> rd.lvm.lv=centos/swap rhgb quiet LANG=de_DE.UTF-8
>               initrd16 /initramfs-3.10.0-327.el7.x86_64.img
> }
> 
> 
> if i remove the comments, the system does not boot, but reboots
> 

This can simply mean that it finds wrong partition and tries to boot
wrong kernel. Add echo before and after search and sleep after last echo
to give time to read it.

> i`m curious why "search" does not simply getting skipped when uuid is not 
> found, as uuid is not being used at all. the menu-entries are NOT configured 
> by hand but by the centos7 installer, so the installer added something to the 
> grub.conf which does not make sense at all, imho. that`s a centos issue, 
> though - but if search would simply be skipped i think it would do no harm 
> and could be simply ignored.
> 
> regards
> roland
> 
> /etc/redhat-release
> CentOS Linux release 7.2.1511 (Core)
> 
> rpm -q -i grub2-2.02-0.34.el7.centos.x86_64
> Name        : grub2
> Epoch       : 1
> Version     : 2.02
> Release     : 0.34.el7.centos
> Architecture: x86_64
> Install Date: Mo 12 Sep 2016 15:29:08 CEST
> Group       : System Environment/Base
> Size        : 7398575
> License     : GPLv3+
> Signature   : RSA/SHA256, Mi 06 Jan 2016 17:54:25 CET, Key ID 24c6a8a7f4a80eb5
> Source RPM  : grub2-2.02-0.34.el7.centos.src.rpm
> Build Date  : Di 05 Jan 2016 18:52:28 CET
> Build Host  : kbuilder.dev.centos.org
> Relocations : (not relocatable)
> URL         : http://www.gnu.org/software/grub/
> Summary     : Bootloader with support for Linux, Multiboot and more
> Description :
> The GRand Unified Bootloader (GRUB) is a highly configurable and customizable
> bootloader with modular architecture.  It support rich varietyof kernel 
> formats,
> file systems, computer architectures and hardware devices.  This subpackage
> provides support for PC BIOS systems.
> 
> 
> 
> 
>> Gesendet: Mittwoch, 14. September 2016 um 10:04 Uhr
>> Von: "Andrei Borzenkov" <address@hidden>
>> An: address@hidden, address@hidden
>> Betreff: Re: grub search - reboot ?
>>
>> 13.09.2016 14:40, address@hidden пишет:
>>> hi,
>>>
>>> i`m curious, what is the expected behaviour of the grub "search"
>>> command?
>>>
>>> i.e. if  i have
>>>
>>> search --no-floppy --fs-uuid --set=root <uuid>
>>>
>>> what should happen if uuid is NOT found ?
>>>
>>
>> Command terminates with error code, variable is not set.
>>
>>> i see my VM reboot (and as Xenserver detects that as "too early after
>>> start and thinks it`s reboot-loop, it powers down the VM).
>>>
>>
>> Why do you think it is related to this command? Add some delay and debug
>> print to make sure where exactly it reboots.
>>
>>> i would expect that search just does not produce any result and grub
>>> continues processing the config, at least it should spit out some
>>> message "uuid not found, resetting..."
>>>
>>> i came across this after cloning a system and transforming the system
>>> disk so that fs-uuid changed, but that should not matter at all, as
>>> the kernel/initrd-statement does not refer to the fs-uuid for
>>> booting....
>>>
>>> regards roland
>>>
>>>
>>> _______________________________________________ Help-grub mailing
>>> list address@hidden 
>>> https://lists.gnu.org/mailman/listinfo/help-grub
>>>
>>
>>