> -----Original Message----- > From: ebiederm at xmission.com > Sent: Sat, 13 Jun 2009 07:08:50 -0700 > To: dseetharam at inbox.com > Subject: Re: /var/log/messages doesn't have crash info when kernel gets > panic/oops/crash > > Dharmosoth Seetharam <dseetharam at inbox.com> writes: > >>>>> Basic questions. >>>>> 1) Do you have panic on oops set? >>>>> I think that setting more than anything else will be the >>>>> difference in what shows up in /var/log/messages. >>>> >>>> Yes, in my case panic_on_oops was set with 1 >>> >>> That is the reason thing don't show up in /var/log/messages >>> because you panic before syslog has a chance to write the messages. >> >> Thanks. >> So, if panic_on_oops set with 0(default), we will get all the >> needed info like stack traces, bug info etc. in /var/log/messages then >> reboots. >> >> Or do we need to apply any specific patches to get info in >> /var/log/messages? >> >>> >>>>> 2) Have you tried a dry run and confirmed you can get a crash dump? >>>> >>>> No, I haven't tried this. >>> >>> It sounds like you have not been getting the coredumps when problems >>> happen. Running a simple test run to Alt-sysrq-c to confirm >>> that things are basically setup ok is a good idea. >>> >> Sorry, I misunderstood your question. >> I have gave dry run and confirmed that the dumps are getting saved in >> particular dir and able to analyze. >> >> I did in both the ways like >> 1 - echo c > /proc/sysrq-trigger >> 2 -Alt -sysrq -c > > Then unless you are having problems capturing core dumps in real > failure situations it sounds like all is well with the world. > > A kernel oops is normally not fatal and the kernel tries to limp along > allowing for better diagnostics etc. This allows klogd to read the > kernels message buffer and pass the kernel messages to syslog which > writes the messages to /var/log/messages. > > After a kernel panic nothing is allowed to happen which prevents > user space from writing to /var/log/messages in the usual way. > > If you want data in /var/log/messages it appears you have two choices. > 1) Post process a core dump as Neil suggested and feed the kernel log > buffer to syslog. > 2) disable panic on oops. The system will continue to limp along > allowing > user space to write to /var/log/messages. > > Eric Thanks Eric. I will try all the ways as you suggested and let you know the outcome. regards, Seetharam ____________________________________________________________ FREE ONLINE PHOTOSHARING - Share your photos online with your friends and family! Visit http://www.inbox.com/photosharing to find out more!
