I''m testing how xen and grub2 can work together.
I''m using xen 3.4.2 and grub2 1.97+20091115-1 from debian sid.
After many failed attempts I''ve discovered that on my system the first
argument that grub2 should pass to the linux kernel is lost.
This is my working grub2 configuration:
menuentry "Xen 3.4.0 / Debian GNU/Linux, Linux 2.6.31-1-xen-amd64" {
insmod xfs
set root=(hd0,2)
multiboot /boot/xen-3.4-amd64.gz
module /boot/vmlinuz-2.6.31-1-xen-amd64 dummy=dummy
root=UUID=e9ed5af4-0503-4314-9d28-415a0eb7b0a0 ro quiet
module /boot/initrd.img-2.6.31-1-xen-amd64
}
Looking in /proc/cmdline, there isn''t any dummy=dummy argument
mnencia@manwe:/tmp$ cat /proc/cmdline
root=UUID=e9ed5af4-0503-4314-9d28-415a0eb7b0a0 ro quiet
Before the addition of dummy=dummy in front of line, the missing
argument was the root=*, so my initrd had no idea of which root it have
to mount.
BTW, the problem happens with both oldschool kernels and pvops ones.
I''ve googled around a bit, but I haven''t found anything about
this issue.
Kind regards,
Marco
--
---------------------------------------------------------------------
| Marco Nenciarini | Debian/GNU Linux Developer - Plug Member |
| mnencia@prato.linux.it | http://www.prato.linux.it/~mnencia |
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Boris Derzhavets
2009-Nov-22 10:48 UTC
Re: [Xen-users] Strange interaction from grub2 and XEN
I switched etc/default/grub :
GRUB_DISABLE_LINUX_UUID=true
and ran:-
# update-grub
Compiled pvops kernel with built in command line:-
root=/dev/sda(x) ro console=tty0
Details here :-
http://bderzhavets.wordpress.com/2009/08/31/loading-xen-via-grub2-on-top-ubuntu-karmic-server-alpha-4/
It works for final 9.10 as well.
Boris.
--- On Sun, 11/22/09, Marco Nenciarini <mnencia@prato.linux.it> wrote:
From: Marco Nenciarini <mnencia@prato.linux.it>
Subject: [Xen-users] Strange interaction from grub2 and XEN
To: xen-users@lists.xensource.com
Date: Sunday, November 22, 2009, 5:27 AM
I''m testing how xen and grub2 can work together.
I''m using xen 3.4.2 and grub2 1.97+20091115-1 from debian sid.
After many failed attempts I''ve discovered that on my system the first
argument that grub2 should pass to the linux kernel is lost.
This is my working grub2 configuration:
menuentry "Xen 3.4.0 / Debian GNU/Linux, Linux 2.6.31-1-xen-amd64" {
insmod xfs
set root=(hd0,2)
multiboot /boot/xen-3.4-amd64.gz
module /boot/vmlinuz-2.6.31-1-xen-amd64 dummy=dummy
root=UUID=e9ed5af4-0503-4314-9d28-415a0eb7b0a0 ro quiet
module /boot/initrd.img-2.6.31-1-xen-amd64
}
Looking in /proc/cmdline, there isn''t any dummy=dummy argument
mnencia@manwe:/tmp$ cat /proc/cmdline
root=UUID=e9ed5af4-0503-4314-9d28-415a0eb7b0a0 ro quiet
Before the addition of dummy=dummy in front of line, the missing argument was
the root=*, so my initrd had no idea of which root it have to mount.
BTW, the problem happens with both oldschool kernels and pvops ones.
I''ve googled around a bit, but I haven''t found anything about
this issue.
Kind regards,
Marco
-- ---------------------------------------------------------------------
| Marco Nenciarini | Debian/GNU Linux Developer - Plug Member |
| mnencia@prato.linux.it | http://www.prato.linux.it/~mnencia |
---------------------------------------------------------------------
Key fingerprint = FED9 69C7 9E67 21F5 7D95 5270 6864 730D F095 E5E4
_______________________________________________
Xen-users mailing list
Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users
_______________________________________________
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Xen-users@lists.xensource.com
http://lists.xensource.com/xen-users
Marco Nenciarini
2009-Nov-22 10:57 UTC
Re: [Xen-users] Strange interaction from grub2 and XEN
Boris Derzhavets ha scritto:> I switched etc/default/grub : > | GRUB_DISABLE_LINUX_UUID=true > and ran:- > # update-grub > Compiled pvops kernel with built in command line:- > root=/dev/sda(x) ro console=tty0This is a workaround, like my dummy argument. I''m looking for a real solution, as find where is the problem and a proper correction, or a rationale that explain what I''m doing wrong. Kind regards, Marco -- --------------------------------------------------------------------- | Marco Nenciarini | Debian/GNU Linux Developer - Plug Member | | mnencia@prato.linux.it | http://www.prato.linux.it/~mnencia | --------------------------------------------------------------------- Key fingerprint = FED9 69C7 9E67 21F5 7D95 5270 6864 730D F095 E5E4 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Marco Nenciarini
2009-Nov-23 09:42 UTC
Re: [Xen-users] Strange interaction from grub2 and XEN
Marco Nenciarini ha scritto:> > I''m testing how xen and grub2 can work together. > > I''m using xen 3.4.2 and grub2 1.97+20091115-1 from debian sid. > > After many failed attempts I''ve discovered that on my system the first > argument that grub2 should pass to the linux kernel is lost. > > This is my working grub2 configuration: > > menuentry "Xen 3.4.0 / Debian GNU/Linux, Linux 2.6.31-1-xen-amd64" { > insmod xfs > set root=(hd0,2) > multiboot /boot/xen-3.4-amd64.gz > module /boot/vmlinuz-2.6.31-1-xen-amd64 dummy=dummy > root=UUID=e9ed5af4-0503-4314-9d28-415a0eb7b0a0 ro quiet > module /boot/initrd.img-2.6.31-1-xen-amd64 > } > > Looking in /proc/cmdline, there isn''t any dummy=dummy argument > > mnencia@manwe:/tmp$ cat /proc/cmdline > root=UUID=e9ed5af4-0503-4314-9d28-415a0eb7b0a0 ro quiet > > Before the addition of dummy=dummy in front of line, the missing > argument was the root=*, so my initrd had no idea of which root it have > to mount. > > BTW, the problem happens with both oldschool kernels and pvops ones. > > I''ve googled around a bit, but I haven''t found anything about this issue.I''ve just found something on this issue in a debian bug report http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=555985#10 Here I quote the interesting part (Felix Zielcke talking of grub): With newest releases you have to double the filename both in multiboot and module line or add a dummy parameter but the filename would reassemble GRUB Legacy''s behaviour. I.e. with 1.97 change it to multiboot /xen-3.4-amd64.gz /xen-3.4-amd64.gz dom0_mem=512M module /vmlinuz-2.6.31.5-xen-00513-g47dfde5 /vmlinuz-2.6.31.5-xen-00513-g47dfde5 nomodeset So is a known issue/feature. Maybe some record of this are needed in xen wiki. Kind Regards, Marco P.S: I''m still curious on why grub2 behaves in this manner. -- --------------------------------------------------------------------- | Marco Nenciarini | Debian/GNU Linux Developer - Plug Member | | mnencia@prato.linux.it | http://www.prato.linux.it/~mnencia | --------------------------------------------------------------------- Key fingerprint = FED9 69C7 9E67 21F5 7D95 5270 6864 730D F095 E5E4 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Marco Nenciarini
2009-Nov-23 16:20 UTC
Re: [Xen-users] Strange interaction from grub2 and XEN
Marco Nenciarini ha scritto:> Boris Derzhavets ha scritto: >> I switched etc/default/grub : >> | GRUB_DISABLE_LINUX_UUID=true >> and ran:- >> # update-grub >> Compiled pvops kernel with built in command line:- >> root=/dev/sda(x) ro console=tty0 > > This is a workaround, like my dummy argument. > > I''m looking for a real solution, as find where is the problem and a > proper correction, or a rationale that explain what I''m doing wrong. > > Kind regards, > Marco >I finally found the the root cause of this issue on grub-devel mailing list. http://lists.gnu.org/archive/html/grub-devel/2009-08/msg00001.html Now I wonder if there is any chance to make the xen hypervisor aware of this behavior change in grub2. Kind regards, Marco -- --------------------------------------------------------------------- | Marco Nenciarini | Debian/GNU Linux Developer - Plug Member | | mnencia@prato.linux.it | http://www.prato.linux.it/~mnencia | --------------------------------------------------------------------- Key fingerprint = FED9 69C7 9E67 21F5 7D95 5270 6864 730D F095 E5E4 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Keir Fraser
2009-Nov-24 17:11 UTC
Re: [Xen-devel] Re: [Xen-users] Strange interaction from grub2 and XEN
On 23/11/2009 16:20, "Marco Nenciarini" <mnencia@prato.linux.it> wrote:>> I''m looking for a real solution, as find where is the problem and a >> proper correction, or a rationale that explain what I''m doing wrong. > > I finally found the the root cause of this issue on grub-devel mailing list. > > http://lists.gnu.org/archive/html/grub-devel/2009-08/msg00001.html > > Now I wonder if there is any chance to make the xen hypervisor aware of > this behavior change in grub2.So they''ve stopped passing the kernel name as a first element of the command line, but haven''t allocated a new flag or anything to indicate that new behaviour? What are we supposed to do to detect it and act on it? -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel
Keir Fraser
2009-Nov-24 17:15 UTC
Re: [Xen-devel] Re: [Xen-users] Strange interaction from grub2 and XEN
On 24/11/2009 17:11, "Keir Fraser" <keir.fraser@eu.citrix.com> wrote:>> Now I wonder if there is any chance to make the xen hypervisor aware of >> this behavior change in grub2. > > So they''ve stopped passing the kernel name as a first element of the command > line, but haven''t allocated a new flag or anything to indicate that new > behaviour? What are we supposed to do to detect it and act on it?Looks like you''re supposed to provide your own dummy first arg, like a ''.'' or something, if booting something that assumes first arg is the kernel name. Seems pretty stupid and unnecessary to change the behaviour I must say. GRUB sucks. -- Keir _______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel