Jump into vmcore analysis – Step 8

There's a time you want to check the local variables or other entries in the stack. Below is an example that was crashed in 'kmem_freepages' and needed to check why it's crashed whiling freeing it. PID: 26 TASK: ffff81027f9197a0 CPU: 0 COMMAND: "events/0" #0 [ffff81027f92fa90] crash_kexec at ffffffff800aaa0c #1 [ffff81027f92fb50] __die at ffffffff8006520f #2 [ffff81027f92fb90]… Continue reading Jump into vmcore analysis – Step 8

Jump into vmcore analysis – Step 6

The real merit of the vmcore is that you can trace the code with the current value each variable holds. Here you can find one example that traces the filesystem which ended up with the corrupted data entry somehow. http://pagead2.googlesyndication.com/pagead/show_ads.js crash> bt PID: 6326 TASK: ffff810402165820 CPU: 1 COMMAND: "fuser" #0 [ffff8103b54efa80] crash_kexec at ffffffff800b099c… Continue reading Jump into vmcore analysis – Step 6

Jump into vmcore analysis – Step 5

With 'bt' command you can check the processes that occupied the CPU at the time of crash. But, there is the time you want to check other processes's backtrace to see what interaction had been established between processes. You can check it by using one of below two methods. crash> set 24960 PID: 24960 COMMAND:… Continue reading Jump into vmcore analysis – Step 5

Jump into vmcore analysis – Step 3

Now we are ready to deep dive into vmcore analysis to confirm what went wrong in the system. In general, first thing I'm checking is the system's log. crash> log .... .... end_request: I/O error, dev sdajm, sector 0 end_request: I/O error, dev sdajm, sector 8 end_request: I/O error, dev sdajm, sector 0 NMI Watchdog… Continue reading Jump into vmcore analysis – Step 3

Jump into a vmcore analysis – Step 1

If you have a vmcore needs to be analysed, you should have to download related kernel-debuginfo package unless your kernel does have all the debug information in the live kernel. You might easily check the kernel version of the vmcore by run 'uname -r', but safest way would be checking vmcore itself. You can use… Continue reading Jump into a vmcore analysis – Step 1