* kexec/ kdump setup problem @ 2008-04-29 3:45 Mrunal Gawade 2008-04-29 11:13 ` Sachin P. Sant 0 siblings, 1 reply; 7+ messages in thread From: Mrunal Gawade @ 2008-04-29 3:45 UTC (permalink / raw) To: kexec [-- Attachment #1.1: Type: text/plain, Size: 901 bytes --] Hi, I have setup the system with two kernels (2.6.25) for kexec/kdump utility. I am using this command to load kernel. Please comment if its correct. vmlinux is the dump kernel. kexec -p /boot/vmlinux --initrd=2.6.25-default-kdump --args-linux --append="root=/dev/sda1 init 1 irqpoll" After I execute this command. Should I expect any prompt that kernel loaded successfully? Because if I execute the sequence alt-SysReq-c after this to force crash my system hangs. Nothing seems to proceed further. How do I check if the kernel is loaded successfully? Because if I execute the "-u" unload option I do not get any error either that kernel is not loaded or something. Nothing seems to happen over there. Your timely help would be much appreciated as I need to get this fixed as soon as possible as my project progress is stopped as I am not able to analyse the reason for crash. Thank you, Mrunal [-- Attachment #1.2: Type: text/html, Size: 965 bytes --] [-- Attachment #2: Type: text/plain, Size: 143 bytes --] _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kexec/ kdump setup problem 2008-04-29 3:45 kexec/ kdump setup problem Mrunal Gawade @ 2008-04-29 11:13 ` Sachin P. Sant 2008-04-29 22:40 ` Mrunal Gawade 0 siblings, 1 reply; 7+ messages in thread From: Sachin P. Sant @ 2008-04-29 11:13 UTC (permalink / raw) To: Mrunal Gawade; +Cc: kexec Mrunal Gawade wrote: > After I execute this command. Should I expect any prompt that kernel > loaded successfully? Check the /sys/kernel/kexec_crash_loaded file. Value "1" means success. Thanks -Sachin _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kexec/ kdump setup problem 2008-04-29 11:13 ` Sachin P. Sant @ 2008-04-29 22:40 ` Mrunal Gawade 2008-04-30 0:17 ` Neil Horman 0 siblings, 1 reply; 7+ messages in thread From: Mrunal Gawade @ 2008-04-29 22:40 UTC (permalink / raw) To: Sachin P. Sant; +Cc: kexec [-- Attachment #1.1: Type: text/plain, Size: 575 bytes --] Thanks Sachin. The value over there is a "0" which means I have a failure. How do I diagnose what is the problem? I was able to load a normal kernel and then use "e" option to reboot into it. But crash dump kernel seemed to be giving problem always. Thank you, Mrunal On Tue, Apr 29, 2008 at 4:13 AM, Sachin P. Sant <sachinp@in.ibm.com> wrote: > Mrunal Gawade wrote: > > > After I execute this command. Should I expect any prompt that kernel > > loaded successfully? > > > Check the /sys/kernel/kexec_crash_loaded file. Value "1" means success. > > Thanks > -Sachin > > [-- Attachment #1.2: Type: text/html, Size: 1032 bytes --] [-- Attachment #2: Type: text/plain, Size: 143 bytes --] _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kexec/ kdump setup problem 2008-04-29 22:40 ` Mrunal Gawade @ 2008-04-30 0:17 ` Neil Horman 2008-04-30 2:14 ` Mrunal Gawade 0 siblings, 1 reply; 7+ messages in thread From: Neil Horman @ 2008-04-30 0:17 UTC (permalink / raw) To: Mrunal Gawade; +Cc: kexec, Sachin P. Sant On Tue, Apr 29, 2008 at 03:40:13PM -0700, Mrunal Gawade wrote: > Thanks Sachin. > > The value over there is a "0" which means I have a failure. How do I > diagnose what is the problem? I was able to load a normal kernel and then > use "e" option to reboot into it. But crash dump kernel seemed to be giving > problem always. > > > Thank you, > Mrunal > check /var/log/messages, to see if there is any message there. It wouldn't hurt to enable debugging in the kexec binary either, although if the load is actually failing, I would think you would get something on stderr. First guess would be that you don't have a crashkernel area specified on your command line (or you do, and its reservation failed, which also will show up in the logs most likely) Neil > On Tue, Apr 29, 2008 at 4:13 AM, Sachin P. Sant <sachinp@in.ibm.com> wrote: > > > Mrunal Gawade wrote: > > > > > After I execute this command. Should I expect any prompt that kernel > > > loaded successfully? > > > > > Check the /sys/kernel/kexec_crash_loaded file. Value "1" means success. > > > > Thanks > > -Sachin > > > > > _______________________________________________ > kexec mailing list > kexec@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/kexec -- /*************************************************** *Neil Horman *Software Engineer *Red Hat, Inc. *nhorman@redhat.com *gpg keyid: 1024D / 0x92A74FA1 *http://pgp.mit.edu ***************************************************/ _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kexec/ kdump setup problem 2008-04-30 0:17 ` Neil Horman @ 2008-04-30 2:14 ` Mrunal Gawade 2008-04-30 4:47 ` Sachin P. Sant 2008-04-30 13:49 ` Neil Horman 0 siblings, 2 replies; 7+ messages in thread From: Mrunal Gawade @ 2008-04-30 2:14 UTC (permalink / raw) To: Neil Horman; +Cc: kexec, Sachin P. Sant [-- Attachment #1.1: Type: text/plain, Size: 2566 bytes --] Hi, I just checked /sys/kernel/kexec_crash_loaded file after giving the kexec -p command for loading panic kernel. And the value was 1. So it was loaded successfully. I then crashed kernel and it hanged. I rebooted manually and checked the value in the file again and it was "0". So across reboot it got reset. So if I assume that the kernel loading was successful, the question remains if it got loaded successfully at the designated space 65M@16M. How do I know that? I am running SUSE 2.6.25 on a VMWare workstation. Does running on VM could change any thing such as memory layout or anything related to panic handling? You specified taking a look at the /sys/kernel/kexec_crash_loaded file. Is there a central document which documents all these error resolving guidelines? Also I checked in the /var/log/messages and there is no message related to this printed over there. Thank you, Mrunal On Tue, Apr 29, 2008 at 5:17 PM, Neil Horman <nhorman@redhat.com> wrote: > On Tue, Apr 29, 2008 at 03:40:13PM -0700, Mrunal Gawade wrote: > > Thanks Sachin. > > > > The value over there is a "0" which means I have a failure. How do I > > diagnose what is the problem? I was able to load a normal kernel and > then > > use "e" option to reboot into it. But crash dump kernel seemed to be > giving > > problem always. > > > > > > Thank you, > > Mrunal > > > > check /var/log/messages, to see if there is any message there. It > wouldn't hurt > to enable debugging in the kexec binary either, although if the load is > actually > failing, I would think you would get something on stderr. First guess > would be > that you don't have a crashkernel area specified on your command line (or > you > do, and its reservation failed, which also will show up in the logs most > likely) > > Neil > > > On Tue, Apr 29, 2008 at 4:13 AM, Sachin P. Sant <sachinp@in.ibm.com> > wrote: > > > > > Mrunal Gawade wrote: > > > > > > > After I execute this command. Should I expect any prompt that kernel > > > > loaded successfully? > > > > > > > Check the /sys/kernel/kexec_crash_loaded file. Value "1" means > success. > > > > > > Thanks > > > -Sachin > > > > > > > > > _______________________________________________ > > kexec mailing list > > kexec@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/kexec > > > -- > /*************************************************** > *Neil Horman > *Software Engineer > *Red Hat, Inc. > *nhorman@redhat.com > *gpg keyid: 1024D / 0x92A74FA1 > *http://pgp.mit.edu > ***************************************************/ > [-- Attachment #1.2: Type: text/html, Size: 3474 bytes --] [-- Attachment #2: Type: text/plain, Size: 143 bytes --] _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kexec/ kdump setup problem 2008-04-30 2:14 ` Mrunal Gawade @ 2008-04-30 4:47 ` Sachin P. Sant 2008-04-30 13:49 ` Neil Horman 1 sibling, 0 replies; 7+ messages in thread From: Sachin P. Sant @ 2008-04-30 4:47 UTC (permalink / raw) To: Mrunal Gawade; +Cc: kexec Mrunal Gawade wrote: > Hi, > > I just checked /sys/kernel/kexec_crash_loaded file after giving the > kexec -p command for loading panic kernel. And the value was 1. So it > was loaded successfully. I then crashed kernel and it hanged. I > rebooted manually and checked the value in the file again and it was > "0". So across reboot it got reset. So if I assume that the kernel > loading was successful, the question remains if it got loaded > successfully at the designated space 65M@16M. How do I know that? The file /sys/kernel/kexec_crash_loaded will have value 1 if the kdump kernel has been loaded successfully. In your case when you executed kexec -p the kernel was loaded at the designated space and value 1 in kexec_crash_loaded reflects that. This value won't be retained across reboots. One will have to again execute the kexec -p command to load the kdump kernel after reboot. [ If kdump service is enabled (chkconfig kdump on) kexec -p will get executed after every reboot. ] I think in your case the problem is that after a successful load, the kdump kernel does not boot on a system crash.[alt-sysrq-c]. you could try adding console related options to the kexec command and see if that will give some information on where the kernel hangs. Thanks -Sachin _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: kexec/ kdump setup problem 2008-04-30 2:14 ` Mrunal Gawade 2008-04-30 4:47 ` Sachin P. Sant @ 2008-04-30 13:49 ` Neil Horman 1 sibling, 0 replies; 7+ messages in thread From: Neil Horman @ 2008-04-30 13:49 UTC (permalink / raw) To: Mrunal Gawade; +Cc: Neil Horman, kexec, Sachin P. Sant On Tue, Apr 29, 2008 at 07:14:36PM -0700, Mrunal Gawade wrote: > Hi, > > I just checked /sys/kernel/kexec_crash_loaded file after giving the kexec -p > command for loading panic kernel. And the value was 1. So it was loaded > successfully. I then crashed kernel and it hanged. I rebooted manually and > checked the value in the file again and it was "0". So across reboot it got > reset. So if I assume that the kernel loading was successful, the question > remains if it got loaded successfully at the designated space 65M@16M. How > do I know that? I am running SUSE 2.6.25 on a VMWare workstation. Does > running on VM could change any thing such as memory layout or anything > related to panic handling? > As Sachin mentioned, kexec_crash_loaded gets reset accross reboots. As for use on a VMWare guest, its behavior is anyones guess. Best thing I could think to do would be to add earlyprintk to the kdump kernel command line, and watch the serial console for mesages about where you're hanging (see Documentations/kernel-parameters.txt for details about earlyprintk). Neil > You specified taking a look at the /sys/kernel/kexec_crash_loaded file. Is > there a central document which documents all these error resolving > guidelines? Also I checked in the /var/log/messages and there is no message > related to this printed over there. > > > Thank you, > Mrunal > > On Tue, Apr 29, 2008 at 5:17 PM, Neil Horman <nhorman@redhat.com> wrote: > > > On Tue, Apr 29, 2008 at 03:40:13PM -0700, Mrunal Gawade wrote: > > > Thanks Sachin. > > > > > > The value over there is a "0" which means I have a failure. How do I > > > diagnose what is the problem? I was able to load a normal kernel and > > then > > > use "e" option to reboot into it. But crash dump kernel seemed to be > > giving > > > problem always. > > > > > > > > > Thank you, > > > Mrunal > > > > > > > check /var/log/messages, to see if there is any message there. It > > wouldn't hurt > > to enable debugging in the kexec binary either, although if the load is > > actually > > failing, I would think you would get something on stderr. First guess > > would be > > that you don't have a crashkernel area specified on your command line (or > > you > > do, and its reservation failed, which also will show up in the logs most > > likely) > > > > Neil > > > > > On Tue, Apr 29, 2008 at 4:13 AM, Sachin P. Sant <sachinp@in.ibm.com> > > wrote: > > > > > > > Mrunal Gawade wrote: > > > > > > > > > After I execute this command. Should I expect any prompt that kernel > > > > > loaded successfully? > > > > > > > > > Check the /sys/kernel/kexec_crash_loaded file. Value "1" means > > success. > > > > > > > > Thanks > > > > -Sachin > > > > > > > > > > > > > _______________________________________________ > > > kexec mailing list > > > kexec@lists.infradead.org > > > http://lists.infradead.org/mailman/listinfo/kexec > > > > > > -- > > /*************************************************** > > *Neil Horman > > *Software Engineer > > *Red Hat, Inc. > > *nhorman@redhat.com > > *gpg keyid: 1024D / 0x92A74FA1 > > *http://pgp.mit.edu > > ***************************************************/ > > -- /*************************************************** *Neil Horman *Software Engineer *Red Hat, Inc. *nhorman@redhat.com *gpg keyid: 1024D / 0x92A74FA1 *http://pgp.mit.edu ***************************************************/ _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2008-04-30 13:49 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2008-04-29 3:45 kexec/ kdump setup problem Mrunal Gawade 2008-04-29 11:13 ` Sachin P. Sant 2008-04-29 22:40 ` Mrunal Gawade 2008-04-30 0:17 ` Neil Horman 2008-04-30 2:14 ` Mrunal Gawade 2008-04-30 4:47 ` Sachin P. Sant 2008-04-30 13:49 ` Neil Horman
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