Using crash utility usage - cannot find booted kernel error (vmlinux)

I'd like to make an analysis   in RH 5.5 for created vmcore file .

According to some docs  two kernel packages are required - kernel-debuginfo-version.arch.rpm and

kernel-debuginfo-common-version.arch.rpm

I have these ones :

# yum list | grep debug

kernel-debug.x86_64                    2.6.18-194.el5        installed
kernel-debug-devel.x86_64              2.6.18-194.el5        installed

Neither kernel-debug-common-* is not available .

I assume that due to this fact  I do not have /usr/lib/debug/lib/modules/ directory with vmlinix in order to proceed with vmcore  analysis .

# crash

........

crash: cannot find booted kernel -- please enter namelist argument

Please advise .

/Vlad .