Hi,
I''m knwe to XEN, and having the usual panic problem.
XEN (3.0.4.1) loads, then the kernel loads, then it says:
"Please append a correct "root=" boot option"
"Not syncying VFS unable to mount root fs on unknown-block(2,0)"
(sort of, I''m catching this just before it reboots !).
I''ve googled, and it seems that the typical two sources of this
problems
are invalid initrd and/or missing drivers in the kernel. So before I turn
mad, I''ve got a bunch of questions I''d be very happy if
somebody could
help me with:
Do you HAVE to have an initrd, or if you managed to put all the necessary
drivers in the kernel, you should be able to boot without an initrd ?
My root partition is formated with JFS. Can this be an issue, or as long
as I have the JFS drivers in the kernel I should be fine ?
Is there a way to capture the console output, short of using the serial
line (or a digital camera :-) ?
Or a way to make it stop and wait for a key to be pressed before it
reboots ?
When I do use an initrd, I get a segfault from the linuxrc.
Depending what version of mkinitrd I use I get different results, a lot of
the time I can''t even mount the gunzip resulting file, and when I can
mount it, I get a lot of empty directories.... Is there a better way of
producing the initrd ?
Thanks.
Yves.
----
Yves Dorfsman yves@zioup.com
http://www.SollerS.ca
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Xen-users mailing list
Xen-users@lists.xensource.com
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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Yves Dorfsman wrote:> > Hi,Hi> > I''m knwe to XEN, and having the usual panic problem. > XEN (3.0.4.1) loads, then the kernel loads, then it says: > "Please append a correct "root=" boot option" > "Not syncying VFS unable to mount root fs on unknown-block(2,0)" > (sort of, I''m catching this just before it reboots !). > > I''ve googled, and it seems that the typical two sources of this problems > are invalid initrd and/or missing drivers in the kernel. So before I > turn mad, I''ve got a bunch of questions I''d be very happy if somebody > could help me with:I''m assuming you''ve already got a root= entry, but I''ve noticed sometimes that what works as the root= under a regular kernel doesn''t under Xen (I''ve noticed this mainly on RHEL systems, they have a tendency to use root=LABEL=/, and under certain Xen kernels (though not on the 2.6.18 that comes with the Xen 3.1 binary) I''ve had to point it to the correct device (though to be fair, it could have been my initrd).> > Do you HAVE to have an initrd, or if you managed to put all the > necessary drivers in the kernel, you should be able to boot without an > initrd ?As long as you have all the driver''s needed to boot the kernel, you should be fine without an initrd> > My root partition is formated with JFS. Can this be an issue, or as long > as I have the JFS drivers in the kernel I should be fine ?Again, as long as you have you have either the driver in the kernel or the module in the initrd, this should be fine. I''ve not come across any xen issues when using non ext3 fs''s myself, but I haven''t tried JFS. I can''t see why it would make a difference.> > Is there a way to capture the console output, short of using the serial > line (or a digital camera :-) ?Sadly not as far as I know. Using a serial console is probably the best way.> > Or a way to make it stop and wait for a key to be pressed before it > reboots ?I add noreboot to the end of the dom0 kernel''s module line in grub (not the kernel line, as that''s Xen, but usually the line below it.> > When I do use an initrd, I get a segfault from the linuxrc. > Depending what version of mkinitrd I use I get different results, a lot > of the time I can''t even mount the gunzip resulting file, and when I can > mount it, I get a lot of empty directories.... Is there a better way of > producing the initrd ? >I always use mkinitrd, and I''ve not had a problem like this before. What distro are you using? Do you put anything weird in your initrd? Are you using the stock binaries from the Xen site, or are you rolling your own? Is mkinitrd returning any errors? Martin> > Thanks. > > > Yves. > ---- > Yves Dorfsman yves@zioup.com > http://www.SollerS.ca > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users-----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGjKhcRnwIDhcMR9MRAsSfAKCyhEeipbr9l9p4fAvkYyd9O70URgCeNcxG OwHAE6OIm8nGCcOBCfQrVAs=n+Za -----END PGP SIGNATURE----- _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Thu, 5 Jul 2007, Martin Goldstone wrote:>> "Please append a correct "root=" boot option" >> "Not syncying VFS unable to mount root fs on unknown-block(2,0)" >> (sort of, I''m catching this just before it reboots !).> I''m assuming you''ve already got a root= entry, but I''ve noticed > sometimes that what works as the root= under a regular kernel doesn''tI have used the same as for my regular kernel: boot=/dev/sda1> under Xen (I''ve noticed this mainly on RHEL systems, they have a > tendency to use root=LABEL=/, and under certain Xen kernels (though not > on the 2.6.18 that comes with the Xen 3.1 binary) I''ve had to point it > to the correct device (though to be fair, it could have been my initrd).>> Do you HAVE to have an initrd, or if you managed to put all the >> necessary drivers in the kernel, you should be able to boot without an >> initrd ? > > As long as you have all the driver''s needed to boot the kernel, you > should be fine without an initrdThanks, that''s what I thought, so I''ll stop wasting my time with initrd for now, and concentrate on the kernel panic itself.>> My root partition is formated with JFS. Can this be an issue, or as long >> as I have the JFS drivers in the kernel I should be fine ? > > Again, as long as you have you have either the driver in the kernel or > the module in the initrd, this should be fine. I''ve not come across anyThanks, that''s what I through.>> Or a way to make it stop and wait for a key to be pressed before it >> reboots ? > > I add noreboot to the end of the dom0 kernel''s module line in grub (not > the kernel line, as that''s Xen, but usually the line below it.Thanks.>> When I do use an initrd, I get a segfault from the linuxrc. >> Depending what version of mkinitrd I use I get different results, a lot >> of the time I can''t even mount the gunzip resulting file, and when I can >> mount it, I get a lot of empty directories.... Is there a better way of >> producing the initrd ? > > I always use mkinitrd, and I''ve not had a problem like this before. > What distro are you using?Gentoo.> Do you put anything weird in your initrd?I let mkinitrd do its stuff. What do you mean by that ?> Are you using the stock binaries from the Xen site, or are you rolling > your own?For xen.gz, I ''ve tried both. For the kernel, I had to build my own, as there is no driver nor module in the "dist" one.> Is mkinitrd returning any errors?Nop.... _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Yves Dorfsman wrote:>- -- snip--> >> Are you using the stock binaries from the Xen site, or are you rolling >> your own? > > For xen.gz, I ''ve tried both. > For the kernel, I had to build my own, as there is no driver nor module > in the "dist" one. >OK, I may be going off on a tangent here, but bear with me. This may sound like a silly question, but when you roll your own kernel, are you building it along with Xen, or are you building it manually? I''ve not built a Xen-patched kernel manually before, so I''m a little unfamiliar with the process, but there are patches to apply (if you are using vanilla sources), and then there are specific settings when configuring. The kernel config file that is in the source tarball from the Xen site should tell you what you need to know. - From what you''ve said though, I''m guessing that there''s a driver you need that is only in a later kernel. If that''s the case, you may need to either port the Xen patches to it yourself (apparently not a task for the faint hearted), or hope someone else has done so (for instance, the latest Ubuntu has a different kernel version to the one on the Xen site). Or you could back port the driver you need. That''s of course if you need a kernel newer than 2.6.18. If you don''t, have you tried Xen 3.1? Of course, I may have got this all wrong. So if you''re using the standard patched sources, and the kernel is configured correctly, my apologies for asking such time wasting questions :-) At any rate, have you managed to capture any useful information from the panic yet? Martin -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGjO56RnwIDhcMR9MRAuiUAJ0RkdnGmje2Ww4MqmGk8nRTrjgkeQCdHHuK zn+NQ8EhMNlQAGTp2xYwTx8=kzyP -----END PGP SIGNATURE----- _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
---------- Forwarded message ---------- From: Galevsky <galevsky@gmail.com> Date: 5 juil. 2007 17:21 Subject: Re: [Xen-users] Kernel panics To: Yves Dorfsman <yves@zioup.com> 2007/7/5, Yves Dorfsman <yves@zioup.com>:> > On Thu, 5 Jul 2007, Martin Goldstone wrote: > > Gentoo. >Hi Yves, I am currently facing pb with a xended kernel on my gentoo box. I emerged =xen-sources-2.6.16.49 and made an oldconfig based on my running gentoo-sources-2.6.20. So that I *should not* have pb with drivers.... I just have to set the xen specific options. I based my dom0 config on http://gentoo-wiki.com/HOWTO_Xen_and_Gentoo. I cannot boot this kernel. No info at all. You can set RC_DEBUG="yes" into the rc conf file, it will generate extra info into boot.log in /var/log. For me, no info at all, neither in dmesg, nor boot.log. I don''t know what to do. I think I will try a no-xen 2.6.16 kernel just to be sure that the pb is coming from the xen kernel config. What was missing in the xen-sources-2.6.16.49 for you ? which driver ? Maybe I face such a problem. Gal'' _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> OK, I may be going off on a tangent here, but bear with me. > > This may sound like a silly question, but when you roll your own kernel, > are you building it along with Xen, or are you building it manually? > I''ve not built a Xen-patched kernel manually before, so I''m a little > unfamiliar with the process, but there are patches to apply (if you are > using vanilla sources), and then there are specific settings when > configuring. The kernel config file that is in the source tarball from > the Xen site should tell you what you need to know.Actually I even tried to use my "normal" 2.6.20 kernel, and XEN told me this wasn''t a XEN kernel and it couldn''t use it. But to answer your question, I got the tar ball, and ran "make world" which pulled the kernel sources from the internet, and added the XEN specific to it. Knowing I needed to add the JFS driver in there, I ran "make oldconfig" "make menuconfig" and added all the drivers into that I thought I neede, then ran a "make" again. Since then, I''ve re-started this from scratch, and I am now making "make world" to split dom0 from domU which cuts down the compile time by a fair bit, but hasn''t changed the results by one bit !> - From what you''ve said though, I''m guessing that there''s a driver you > need that is only in a later kernel. If that''s the case, you may needHmmmm... I thought about that for about 5 seconds, I do have a fairly recent AM2 mother board, and my current kernel is 2.6.20. I''ll pull the 2.6.16 from kernel.org, and see if I can boot from that.> to either port the Xen patches to it yourself (apparently not a task for > the faint hearted), or hope someone else has done so (for instance, the > latest Ubuntu has a different kernel version to the one on the Xen > site). Or you could back port the driver you need. That''s of course if > you need a kernel newer than 2.6.18. If you don''t, have you tried Xen > 3.1?I did quickly tried XEN 3.1, but got the same results...> Of course, I may have got this all wrong. So if you''re using the > standard patched sources, and the kernel is configured correctly, my > apologies for asking such time wasting questions :-)Don''t worry, I appreciate your help, makes me re-think all the steps I have done, so that might even trigger good ideas (the old "ask Bob" effect).> At any rate, have you managed to capture any useful information from the > panic yet?What is "useful" information, beyond the message I posted in an earlier post ? And how can I get the output to be more verbose than that ? Yves. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> I am currently facing pb with a xended kernel on my gentoo box. I > emerged =xen-sources-2.6.16.49 and made an oldconfig based on my > running gentoo-sources-2.6.20. So that I *should not* have pb with > drivers.... I just have to set the xen specific options. I based my > dom0 config onI actually gave up on this one, "make menuconfig" wasn''t showing me the XEN options, and didn''t have arch/xen directories, so I assumed there was something wrong in it. I pulled the tar ball for the xen web site. It does bring up an interesting point though, the one from the tar ball is based on 2.6.16-33 rather than -49.> http://gentoo-wiki.com/HOWTO_Xen_and_Gentoo.Yes, I have used that document.> I cannot boot this kernel. No info at all. You can set RC_DEBUG="yes" > into the rc conf file, it will generate extra info into boot.log in > /var/log.You mean it does not even start booting up, or does it end up panic''ing ? Are you using an initrd ? What version of mkinitrd do you use (gentoo stable has tree right now) ?> For me, no info at all, neither in dmesg, nor boot.log. I don''t know > what to do. I think I will try a no-xen 2.6.16 kernel just to be sure > that the pb is coming from the xen kernel config.But... the XEN''ed kernel cannot write to the filesystem until it has managed to mount it, from what you are saying you don''t get to that point, do you ?> What was missing in the xen-sources-2.6.16.49 for you ? which driver ? > Maybe I face such a problem.Well JFS for sure, since my partition is JFS, but obviously something else too that I am not aware of :-( Yves. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
---------- Forwarded message ---------- From: Galevsky <galevsky@gmail.com> Date: 5 juil. 2007 22:58 Subject: Re: [Xen-users] Kernel panics To: Yves Dorfsman <yves@zioup.com> 2007/7/5, Yves Dorfsman <yves@zioup.com>:> > > I am currently facing pb with a xended kernel on my gentoo box. I > > emerged =xen-sources-2.6.16.49 and made an oldconfig based on my > > running gentoo-sources-2.6.20. So that I *should not* have pb with > > drivers.... I just have to set the xen specific options. I based my > > dom0 config on > > I actually gave up on this one, "make menuconfig" wasn''t showing me > the XEN options, and didn''t have arch/xen directories, so I assumed > there was something wrong in it. I pulled the tar ball for the xen > web site. It does bring up an interesting point though, the one > from the tar ball is based on 2.6.16-33 rather than -49.okay... for me oldconfig (and also menuconfig) brings me new xen-options menu.> > http://gentoo-wiki.com/HOWTO_Xen_and_Gentoo. > > Yes, I have used that document. > > > I cannot boot this kernel. No info at all. You can set RC_DEBUG="yes" > > into the rc conf file, it will generate extra info into boot.log in > > /var/log. > > You mean it does not even start booting up, or does it end up panic''ing ? > Are you using an initrd ? What version of mkinitrd do you use (gentoo > stable has tree right now) ?I am praying all the penguins to run into K panics.... but what I face is no boot at all, so, no little piece of log.> > For me, no info at all, neither in dmesg, nor boot.log. I don''t know > > what to do. I think I will try a no-xen 2.6.16 kernel just to be sure > > that the pb is coming from the xen kernel config. > > But... the XEN''ed kernel cannot write to the filesystem until it has > managed to mount it, from what you are saying you don''t get to that > point, do you ?you''re right, but I am riding an ext3 fs which support is included into the kernel itself, so I *should not* face fs problems.... but I be sure... since no log. What''s wrong on that kernel ? no idea. I retrieved the fs/network/optim/ options (all built into the kernel, no module to be sure) from the running kernel via make oldconfig ....> > What was missing in the xen-sources-2.6.16.49 for you ? which driver ? > > Maybe I face such a problem. > > Well JFS for sure, since my partition is JFS, but obviously something > else too that I am not aware of :-( >JFS sounds sensible in your case :o). Maybe I am coming up against the dark side of the dark force you faced before :o(. Well, it is my first try with xen, and I have no idea about patching vanilla sources to make them xen compatible -xen-sources are in for that purpose- but if you tell me it is not a hard pain, I can have a deeper eye on it. Gal'' _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Yves Dorfsman
2007-Jul-06 14:04 UTC
Re: [Xen-users] gentoo not booting ( was Kernel panics)
On Thu, 5 Jul 2007, Galevsky wrote:>> But... the XEN''ed kernel cannot write to the filesystem until it has >> managed to mount it, from what you are saying you don''t get to that >> point, do you ? > > you''re right, but I am riding an ext3 fs which support is included > into the kernel itself, so I *should not* face fs problems.... but I > be sure... since no log. What''s wrong on that kernel ? no idea. I > retrieved the fs/network/optim/ options (all built into the kernel, no > module to be sure) from the running kernel via make oldconfig ....Well, it needs to boot and mount the filesystem before it can write to it. You''re saying it does not even boot.> Well, it is my first try with xen, and I have no idea about patching > vanilla sources to make them xen compatible -xen-sources are in for > that purpose- but if you tell me it is not a hard pain, I can have a > deeper eye on it.This is my first try too, and I haven''t been successfull yet, so I''m not sure that I should give advice, but, I don''t understand what you mean by it does not boot. What boot loader do you use (grub ?) ? Once you tell it to boot, what happens, does it reboot right away and come back to the boot loader, or do you get the "XEN: xxx" mesages, and then it stops and reboot ? Is your kernerl instruction pointing to a valid xen.gz ? Yves. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, I am using grub, and I know that I was not pointing to a good xen.gz. So, I will get ahead and let you know if other problems happen. Thanks for your help ;o) Gal'' 2007/7/6, Yves Dorfsman <yves@zioup.com>:> > On Thu, 5 Jul 2007, Galevsky wrote: > > >> But... the XEN''ed kernel cannot write to the filesystem until it has > >> managed to mount it, from what you are saying you don''t get to that > >> point, do you ? > > > > you''re right, but I am riding an ext3 fs which support is included > > into the kernel itself, so I *should not* face fs problems.... but I > > be sure... since no log. What''s wrong on that kernel ? no idea. I > > retrieved the fs/network/optim/ options (all built into the kernel, no > > module to be sure) from the running kernel via make oldconfig .... > > Well, it needs to boot and mount the filesystem before it can write to it. > You''re saying it does not even boot. > > > Well, it is my first try with xen, and I have no idea about patching > > vanilla sources to make them xen compatible -xen-sources are in for > > that purpose- but if you tell me it is not a hard pain, I can have a > > deeper eye on it. > > This is my first try too, and I haven''t been successfull yet, so I''m not > sure that I should give advice, but, I don''t understand what you mean by > it does not boot. What boot loader do you use (grub ?) ? > > Once you tell it to boot, what happens, does it reboot right away and come > back to the boot loader, or do you get the "XEN: xxx" mesages, and then it > stops and reboot ? > > Is your kernerl instruction pointing to a valid xen.gz ? > > > Yves. > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users