Xen core dump analysis
After the Xen guest domain hangs, I took a dump using xm core-dump. Following the sparse documentation I found, I tried to use the crash utility to analyze the dump.
Unfortunately the kernel image (Debian lenny) is removed, so I have to use the map file.
However
crash /boot/System.map-2.6.26-2-xen-amd64 vmlinux-2.6.26-2-xen-amd64 / highway / my-kernel file
(with vmlinux-2.6.26-2-xen-amd64 being the vmlinuz gunzip 'image) fails:
crash: vmlinux-2.6.26-2-xen-amd64: no debug data available
Then I read that current versions of Xen generate ELF compliant dumps for guest domains. Indeed, it looks like this:
~ $ sudo file my-core-dump
my-core-dump: ELF 64-bit LSB base file x86-64 version 1
However, gdb vmlinux-2.6.26-2-xen-amd64 my-core-dump also does not work:
... is not a core dump: the file format is not recognized
Any hints?
Have you tried to connect to the domU console?
xm create domU.conf -c
Regarding the core-dump file, I found the following:
http://lists.xensource.com/archives/html/xen-devel/2006-12/msg00456.html
I just want to check that you don't have the impression that "xm dump-core 'is emitting an Elf core file. It is not - the format is normal and, as far as I know, is only interpreted by the set of gdbserver patches that we submit to our repository. does disaster recovery really support this special format?
Edit: this might help debug core-dump: http://os-drive.com/files/docbook/xen-faq.html#setup_gdb
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