Re: [gentoo-user] New kernel does not boot up on remote host
Many thanks for you suggestion. I tried a boot with no fall back, but nothing added neither to boot.log nor to dmesg. I am sure to target the right kernel image with no typo into grub.conf . This new kernel is a =xen-sources-2.6.16.49, and I configured it making an oldconfig based on current =gentoo-sources-2.6.20 running kernel. So, errors cannot come from drivers or such things, but specific xen options. Does anyone know any xen option able to prevent the kernel to boot up ? Many thanks for your support, Gal' 2007/7/4, Albert Hopkins [EMAIL PROTECTED]: On Wed, 2007-07-04 at 21:54 +0200, Galevsky wrote: ... the matter is Grub falls back to previous 2.6.20 kernel. So I have no log at all about what went wrong during the dom0_2.6.18 boot. Any idea to know what went wrong ? Nevertheless, if you want to actually know what the error is then you should disable the fallback. -- Albert W. Hopkins -- [EMAIL PROTECTED] mailing list -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] New kernel does not boot up on remote host
On Thu, 2007-07-05 at 11:36 +0200, Galevsky wrote: Many thanks for you suggestion. I tried a boot with no fall back, but nothing added neither to boot.log nor to dmesg. I am sure to target the right kernel image with no typo into grub.conf . This new kernel is a =xen-sources-2.6.16.49, and I configured it making an oldconfig based on current =gentoo-sources-2.6.20 running kernel. So, errors cannot come from drivers or such things, but specific xen options. Does anyone know any xen option able to prevent the kernel to boot up ? I guess I (still) don't understand what your issue is. So I went back and read your original post. Maybe I misunderstood it. * What do you mean by remote host? * If your box does not boot how would you expect to see a boot.log or dmesg? They don't exist if the system has not booted. In fact does not boot implies that you can't even log in to check for dmesg or boot logs. Perhaps you can explain what it is exactly you mean by does not boot. * Usually there is an error message on the console if there is a boot loader/kernel issue with booting. * Also you never posted your grub.conf. So hopefully you can come up with a specific explanation of does not boot as well as your config and any console messages you get. Else this becomes a blind leading the blind issue. -- Albert W. Hopkins -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] New kernel does not boot up on remote host
2007/7/5, Albert Hopkins [EMAIL PROTECTED]: On Thu, 2007-07-05 at 11:36 +0200, Galevsky wrote: Many thanks for you suggestion. I tried a boot with no fall back, but nothing added neither to boot.log nor to dmesg. I am sure to target the right kernel image with no typo into grub.conf . This new kernel is a =xen-sources-2.6.16.49, and I configured it making an oldconfig based on current =gentoo-sources-2.6.20 running kernel. So, errors cannot come from drivers or such things, but specific xen options. Does anyone know any xen option able to prevent the kernel to boot up ? I guess I (still) don't understand what your issue is. So I went back and read your original post. Maybe I misunderstood it. * What do you mean by remote host? I rent a dedicated host. Thus, I have no physical access to the machine. And the reason why I used the fall-back feature into grub is to avoid the use of a boring rescue system (via a web interface) to take back the control of a not-responding box. * If your box does not boot how would you expect to see a boot.log or dmesg ? They don't exist if the system has not booted. In fact does not boot implies that you can't even log in to check for dmesg or boot logs. Perhaps you can explain what it is exactly you mean by does not boot. When I try to boot on the new kernel, I set it as the default one in grub.conf and reboot the box. And I wait for a few minutes. Then I try to log on, praying to find the box responding. First, with grub fall-back activated, the boot had fallen back and I was able to read the logs that contained the running kernel logs, but no info about the kernel boot that failed. That was the matter of my first mail: how to read the reasons of the first kernel-boot-attempt failure. Secondly, you advised me to turn fall back off. I do. The box is no more responding after reboot, and I have to launch the rescue system to log on my box, and read the /var/log/*. I thought previously that some pb happened -I didn't know when exactly-... and was waiting for more info in log files. But files were empty. So, I conclude that the boot procedure failed (and you too ;o)). Finally, I have to find out why my kernel is not booting. I tuned up well my previous kernel, a gentoo-sources-2.6.20 -this kernel runs currently my box very well- and the kernel I want to boot now is a xen-sources-2.6.16. I made an oldconfig on /proc/config.gz of the 2.6.20 running kernel, and fill in xen-dom0 specific options as indicated on the wiki tutorial [1]. So, I guess I did something wrong with the dom0 xen config, and asked for advice on xen specific options with my second post. * Usually there is an error message on the console if there is a boot loader/kernel issue with booting. * Also you never posted your grub.conf. So hopefully you can come up with a specific explanation of does not boot as well as your config and any console messages you get. Else this becomes a blind leading the blind issue. I have no console message to provide you, I just know that my remote box is not responding when I try to boot another kernel (If you know the way to get logs, I'll be grateful :o)). And I checked the /var/log/* to be sure that the kernel was not running but just missing any network feature so that I could not log on the box despite the kernel was actually running. As for my grub.conf + 'ls -l /boot' , I will provide you in a while (I need to go home before), but I am not sure it is relevant. (just to check for typo I guess). -- Albert W. Hopkins -- [EMAIL PROTECTED] mailing list Many thanks to take care of my problem :o) Gal' [1]: http://gentoo-wiki.com/HOWTO_Xen_and_Gentoo -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] New kernel does not boot up on remote host
On Thu, 5 Jul 2007 18:40:20 +0200 Galevsky [EMAIL PROTECTED] wrote: 2007/7/5, Albert Hopkins [EMAIL PROTECTED]: On Thu, 2007-07-05 at 11:36 +0200, Galevsky wrote: Many thanks for you suggestion. I tried a boot with no fall back, but nothing added neither to boot.log nor to dmesg. I am sure to target the right kernel image with no typo into grub.conf . This new kernel is a =xen-sources-2.6.16.49, and I configured it making an oldconfig based on current =gentoo-sources-2.6.20 running kernel. So, errors cannot come from drivers or such things, but specific xen options. Does anyone know any xen option able to prevent the kernel to boot up ? I guess I (still) don't understand what your issue is. So I went back and read your original post. Maybe I misunderstood it. * What do you mean by remote host? I rent a dedicated host. Thus, I have no physical access to the machine. And the reason why I used the fall-back feature into grub is to avoid the use of a boring rescue system (via a web interface) to take back the control of a not-responding box. * If your box does not boot how would you expect to see a boot.log or dmesg ? They don't exist if the system has not booted. In fact does not boot implies that you can't even log in to check for dmesg or boot logs. Perhaps you can explain what it is exactly you mean by does not boot. When I try to boot on the new kernel, I set it as the default one in grub.conf and reboot the box. And I wait for a few minutes. Then I try to log on, praying to find the box responding. First, with grub fall-back activated, the boot had fallen back and I was able to read the logs that contained the running kernel logs, but no info about the kernel boot that failed. That was the matter of my first mail: how to read the reasons of the first kernel-boot-attempt failure. Secondly, you advised me to turn fall back off. I do. The box is no more responding after reboot, and I have to launch the rescue system to log on my box, and read the /var/log/*. I thought previously that some pb happened -I didn't know when exactly-... and was waiting for more info in log files. But files were empty. So, I conclude that the boot procedure failed (and you too ;o)). Finally, I have to find out why my kernel is not booting. I tuned up well my previous kernel, a gentoo-sources-2.6.20 -this kernel runs currently my box very well- and the kernel I want to boot now is a xen-sources-2.6.16. I made an oldconfig on /proc/config.gz of the 2.6.20 running kernel, and fill in xen-dom0 specific options as indicated on the wiki tutorial [1]. So, I guess I did something wrong with the dom0 xen config, and asked for advice on xen specific options with my second post. * Usually there is an error message on the console if there is a boot loader/kernel issue with booting. * Also you never posted your grub.conf. So hopefully you can come up with a specific explanation of does not boot as well as your config and any console messages you get. Else this becomes a blind leading the blind issue. I have no console message to provide you, I just know that my remote box is not responding when I try to boot another kernel (If you know the way to get logs, I'll be grateful :o)). And I checked the /var/log/* to be sure that the kernel was not running but just missing any network feature so that I could not log on the box despite the kernel was actually running. As for my grub.conf + 'ls -l /boot' , I will provide you in a while (I need to go home before), but I am not sure it is relevant. (just to check for typo I guess). -- Albert W. Hopkins -- [EMAIL PROTECTED] mailing list Many thanks to take care of my problem :o) Gal' [1]: http://gentoo-wiki.com/HOWTO_Xen_and_Gentoo from /etc/conf.d/rc: # RC_BOOTLOG will generate a log of the boot messages shown on the console. # Useful for headless machines or debugging. You need to emerge the # app-admin/showconsole package for this to work. Note that this probably # won't work correctly with boot splash. RC_BOOTLOG=no I recommend you install showconsole and set RC_BOOTLOG to yes, that might help you. It is possible that maybe something as mundane as networking is failing for a stupid reason, and therefore you cant get to the computer because it cant finish booting. -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] New kernel does not boot up on remote host
I recently discovered 'savefallback' in grub which I did not know about. I'll assume you're using that but again, I haven't seen your grub.conf. Dan Farrell made an intresting point about boot log and showconsole, but I assumed you were already using that. But I still don't that will help you because your problem appears to be one of the following: * Grub is not loading your kernel and is falling back (same as my original theory) * Your kernel/hypervisor is loading but is crashing immediately. If the Xen hypervisor is crashing you really need the console. AFAIK there's no option to log. The only option you really have is whether or not to immediately reboot when it crashes. If Xen is loading successfully then it loads your dom0. If that's crashing it's probably crashing immediately (i.e. not even mounting root). If it is the dom0 then that seems to be the case since you can't find any record of it having booted. If you crash before you mount root read/write then showconsole and bootlog are useless. All things said, I'm still guessing that it's either a grub problem or Xen doesn't like your hardware. Xen is picky about hardware and sometimes you have to turn on/off things in the BIOS or as a parameter to Xen (like the ACPI controller) but it's going to be hard to guess without an error message and I'm betting that error message appears before bootlog/showconsole take effect. -- Albert W. Hopkins -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] New kernel does not boot up on remote host
2007/7/5, Dan Farrell [EMAIL PROTECTED]: On Thu, 5 Jul 2007 18:40:20 +0200 Galevsky [EMAIL PROTECTED] wrote: 2007/7/5, Albert Hopkins [EMAIL PROTECTED]: On Thu, 2007-07-05 at 11:36 +0200, Galevsky wrote: Many thanks for you suggestion. I tried a boot with no fall back, but nothing added neither to boot.log nor to dmesg. I am sure to target the right kernel image with no typo into grub.conf . This new kernel is a =xen-sources-2.6.16.49, and I configured it making an oldconfig based on current =gentoo-sources-2.6.20 running kernel. So, errors cannot come from drivers or such things, but specific xen options. Does anyone know any xen option able to prevent the kernel to boot up ? I guess I (still) don't understand what your issue is. So I went back and read your original post. Maybe I misunderstood it. * What do you mean by remote host? I rent a dedicated host. Thus, I have no physical access to the machine. And the reason why I used the fall-back feature into grub is to avoid the use of a boring rescue system (via a web interface) to take back the control of a not-responding box. * If your box does not boot how would you expect to see a boot.log or dmesg ? They don't exist if the system has not booted. In fact does not boot implies that you can't even log in to check for dmesg or boot logs. Perhaps you can explain what it is exactly you mean by does not boot. When I try to boot on the new kernel, I set it as the default one in grub.conf and reboot the box. And I wait for a few minutes. Then I try to log on, praying to find the box responding. First, with grub fall-back activated, the boot had fallen back and I was able to read the logs that contained the running kernel logs, but no info about the kernel boot that failed. That was the matter of my first mail: how to read the reasons of the first kernel-boot-attempt failure. Secondly, you advised me to turn fall back off. I do. The box is no more responding after reboot, and I have to launch the rescue system to log on my box, and read the /var/log/*. I thought previously that some pb happened -I didn't know when exactly-... and was waiting for more info in log files. But files were empty. So, I conclude that the boot procedure failed (and you too ;o)). Finally, I have to find out why my kernel is not booting. I tuned up well my previous kernel, a gentoo-sources-2.6.20 -this kernel runs currently my box very well- and the kernel I want to boot now is a xen-sources-2.6.16. I made an oldconfig on /proc/config.gz of the 2.6.20 running kernel, and fill in xen-dom0 specific options as indicated on the wiki tutorial [1]. So, I guess I did something wrong with the dom0 xen config, and asked for advice on xen specific options with my second post. * Usually there is an error message on the console if there is a boot loader/kernel issue with booting. * Also you never posted your grub.conf. So hopefully you can come up with a specific explanation of does not boot as well as your config and any console messages you get. Else this becomes a blind leading the blind issue. I have no console message to provide you, I just know that my remote box is not responding when I try to boot another kernel (If you know the way to get logs, I'll be grateful :o)). And I checked the /var/log/* to be sure that the kernel was not running but just missing any network feature so that I could not log on the box despite the kernel was actually running. As for my grub.conf + 'ls -l /boot' , I will provide you in a while (I need to go home before), but I am not sure it is relevant. (just to check for typo I guess). -- Albert W. Hopkins -- [EMAIL PROTECTED] mailing list Many thanks to take care of my problem :o) Gal' [1]: http://gentoo-wiki.com/HOWTO_Xen_and_Gentoo from /etc/conf.d/rc: # RC_BOOTLOG will generate a log of the boot messages shown on the console. # Useful for headless machines or debugging. You need to emerge the # app-admin/showconsole package for this to work. Note that this probably # won't work correctly with boot splash. RC_BOOTLOG=no I recommend you install showconsole and set RC_BOOTLOG to yes, that might help you. It is possible that maybe something as mundane as networking is failing for a stupid reason, and therefore you cant get to the computer because it cant finish booting. -- [EMAIL PROTECTED] mailing list Thank you Dan, but I did it before, and boot.log remains empty. In fact, the new kernel boot turns on like grub couldn't find the kernel image Hereafter my /boot content: sd-4421 boot # ll /boot total 13M -rw-rw-r-- 1 root root 767k Jul 6 00:02 System.map-2.6.16.49-xendedibox_r6_final -rw-r--r-- 1 root root 929k Jun 16 19:29 System.map-2.6.20-gentoo-r8 lrwxrwxrwx 1 root root1 Apr 30 19:40 boot - ./ -rw-rw-r-- 1 root root 31k Jul 6 00:02 config-2.6.16.49-xendedibox_r6_final
Re: [gentoo-user] New kernel does not boot up on remote host
Sorry, I was building again my kernel image to confirm that It was not a stupid mistake. 2007/7/6, Albert Hopkins [EMAIL PROTECTED]: I recently discovered 'savefallback' in grub which I did not know about. I'll assume you're using that but again, I haven't seen your grub.conf. Dan Farrell made an intresting point about boot log and showconsole, but I assumed you were already using that. Ya, I did it. No boot.log created when booting the xen-kernel, but reporting good status when I boot up the good 2.6.20 one. So, feature is on. But I still don't that will help you because your problem appears to be one of the following: * Grub is not loading your kernel and is falling back (same as my original theory) Ya, you should be right... * Your kernel/hypervisor is loading but is crashing immediately. If the Xen hypervisor is crashing you really need the console. AFAIK there's no option to log. The only option you really have is whether or not to immediately reboot when it crashes. If Xen is loading successfully then it loads your dom0. If that's crashing it's probably crashing immediately (i.e. not even mounting root). If it is the dom0 then that seems to be the case since you can't find any record of it having booted. If you crash before you mount root read/write then showconsole and bootlog are useless. All things said, I'm still guessing that it's either a grub problem or Xen doesn't like your hardware. Xen is picky about hardware and sometimes you have to turn on/off things in the BIOS or as a parameter to Xen (like the ACPI controller) but it's going to be hard to guess without an error message and I'm betting that error message appears before bootlog/showconsole take effect. Okay, thanks a lot, I am looking for such information since I am new to xen. I will google for people running xen solutions on the same kind of boxes. -- Albert W. Hopkins -- [EMAIL PROTECTED] mailing list Many thanks for your support guys ;o) Gal' -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] New kernel does not boot up on remote host
Galevsky wrote: Thank you Dan, but I did it before, and boot.log remains empty. In fact, the new kernel boot turns on like grub couldn't find the kernel image SNIP and my grub.conf: ### START (grub.conf) sd-4421 boot # cat /boot/grub/grub.conf # Customized boot procedure default 0 timeout 1 #fallback 1 2 title Gentoo Linux 2.6.16-gentoo_xen_dom0 root (hd0,0) kernel /boot/vmlinuz-2.6-xen ro root=/dev/sda2 title Gentoo Linux 2.6.20-r8 root (hd0,0) kernel /boot/vmlinuz-2.6.20-gentoo-r8 ro root=/dev/sda2 title Gentoo Linux 2.6.18-r4-dedibox_r6_final root (hd0,0) kernel /boot/ref/2.6.18-gentoo-r4dedibox_r6_final ro root=/dev/sda2 ### END (grub.conf) Well, let's try a boot on kernel /boot/vmlinuz-2.6-xen = box not responding. and via the rescue system: # ls /mnt/sda2/var/log/ portage user.log xen # more /mnt/sda2/var/log/user.log Jul 6 00:12:30 sd-4421 shutdown[4571]: shutting down for system reboot thus no log at all (xen log also empty). Gal' This is my grub.conf entry: title Gentoo new kernel kernel (hd0,0)/bzImage-2.6.20-r8-3 root=/dev/hda6 ide0=ata66 ide1=ata66 vga=788 Note the missing /boot before the kernel? If you have /boot on a separate partition, you need to remove the /boot and make it read something like kernel /vmlinuz-2.6.20-gentoo-r8 ro root=/dev/sda2 Keep in mind, the root partition is not mounted when it loads the kernel. That is mounted later. I hope that helps. Dale :-) :-) -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] New kernel does not boot up on remote host
On Fri, 2007-07-06 at 00:44 +0200, Galevsky wrote: and my grub.conf: ### START (grub.conf) sd-4421 boot # cat /boot/grub/grub.conf # Customized boot procedure default 0 timeout 1 #fallback 1 2 title Gentoo Linux 2.6.16-gentoo_xen_dom0 root (hd0,0) kernel /boot/vmlinuz-2.6-xen ro root=/dev/sda2 title Gentoo Linux 2.6.20-r8 root (hd0,0) kernel /boot/vmlinuz-2.6.20-gentoo-r8 ro root=/dev/sda2 title Gentoo Linux 2.6.18-r4-dedibox_r6_final root (hd0,0) kernel /boot/ref/2.6.18-gentoo-r4dedibox_r6_final ro root=/dev/sda2 ### END (grub.conf) Wow, it really does make a difference when we can see the configuration! Actually you are not using savedefault like I was assuming. Which basically means fallback only works when grub fails to load the kernel. You said you followed the HOWTO Xen and Gentoo but looks like you ignored section 6 on configuring the boot loader. It should look more like this: title Gentoo Linux 2.6.16-gentoo_xen_dom0 root (hd0,0) kernel /boot/xen.gz dom0_mem=98M module /boot/vmlinuz-2.6.20-gentoo-r8 ro root=/dev/sda2 Likely the dom0 kernel is failing because it expects to be run within the hypervisor. You need to load that first as in the above. Hope this helps. -- Albert W. Hopkins -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] New kernel does not boot up on remote host
On Wed, 2007-07-04 at 21:54 +0200, Galevsky wrote: ... the matter is Grub falls back to previous 2.6.20 kernel. So I have no log at all about what went wrong during the dom0_2.6.18 boot. Any idea to know what went wrong ? Fall back is usually useless in the sense that if grub finds your kernel and can boot it, but it happens to be a bad kernel, then there is no benefit. If/Since you *are* falling back leads me to believe that grub either can't find your kernel or otherwise can't load it (typo in grub.conf). Nevertheless, if you want to actually know what the error is then you should disable the fallback. -- Albert W. Hopkins -- [EMAIL PROTECTED] mailing list
