[Crash-utility] How does crash find booted kernel?

[Nan Xiao]

Hi Buland,

Firstly, thanks for your comments!

Executing the following commands:

[root at localhost ktap]# uname -r
3.10.0-123.el7.x86_64.debug

[root at localhost ktap]# rpm -q kernel-debuginfo
kernel-debuginfo-3.10.0-123.el7.x86_64

[root at localhost ktap]# rpm -q kernel
kernel-3.10.0-123.el7.x86_64

It seems all the versions are match. So I think it is not this issue, thanks!
Best Regards
Nan Xiao


On Mon, Nov 2, 2015 at 3:15 PM, Buland Kumar Singh
<6b65726e656c at gmail.com> wrote:
> On 2 November 2015 at 09:09, Nan Xiao <xiaonan830818 at gmail.com> wrote:
>>
>> Hi all,
>>
>> I am trying to use crash on RHEL 7.0.After executing "crash" command,
>> it outputs:
>>
>>     crash: cannot find booted kernel -- please enter namelist argument
>>
>> After referring to crash white paper
>> (https://people.redhat.com/anderson/crash_whitepaper/),
>> I know it needs vmlinux file. So I install "kernel-debuginfo" package:
>>
>> [root at localhost boot]# rpm -ql kernel-debuginfo | grep vmlinux
>> /usr/lib/debug/lib/modules/3.10.0-123.el7.x86_64/vmlinux
>>
>> Then execute crash, it still prompts the same error:
>>
>>     crash: cannot find booted kernel -- please enter namelist argument
>>
>> I try to copy vmlinux file into /boot directory, but this error still
>> exists.
>>
>> How can I fix this issue? Thanks very much in advance!
>>
>> Best Regards
>> Nan Xiao
>>
>> --
>> Crash-utility mailing list
>> Crash-utility at redhat.com
>> https://www.redhat.com/mailman/listinfo/crash-utility
>
>
>
> Hi Nan,
>
> You need to make sure that the version of kernel-debuginfo package must
> match with the version of running kernel.
>
> Eg:
> # rpm -q kernel
> kernel-3.10.0-229.el7.x86_64
>
> # uname -r
> 3.10.0-229.el7.x86_64
>
> # rpm -q kernel-debuginfo
> package kernel-debuginfo is not installed
>
> # rpm -ivh kernel-debuginfo-common-x86_64-3.10.0-229.el7.x86_64.rpm
> Preparing...                          #################################
> [100%]
> Updating / installing...
>    1:kernel-debuginfo-common-x86_64-3.#################################
> [100%]
>
> # rpm -ivh kernel-debuginfo-3.10.0-229.el7.x86_64.rpm
> Preparing...                          #################################
> [100%]
> Updating / installing...
>    1:kernel-debuginfo-3.10.0-229.el7  #################################
> [100%]
>
> # rpm -q kernel-debuginfo
> kernel-debuginfo-3.10.0-229.el7.x86_64
>
> # crash -s
>
> crash> sys
>       KERNEL: /usr/lib/debug/lib/modules/3.10.0-229.el7.x86_64/vmlinux
>     DUMPFILE: /dev/crash
>         CPUS: 2
>         DATE: Mon Nov  2 12:41:58 2015
>       UPTIME: 00:13:18
> LOAD AVERAGE: 0.37, 0.37, 0.18
>        TASKS: 122
>     NODENAME: localhost.localdomain
>      RELEASE: 3.10.0-229.el7.x86_64
>      VERSION: #1 SMP Thu Jan 29 18:37:38 EST 2015
>      MACHINE: x86_64  (2790 Mhz)
>       MEMORY: 2 GB
>
> --
> BKS
>
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