Getting dumps of Xen/KVM virtual machines with virsh (for CentOS 6/7 host)

1. Make sure you have libvirt tools installed on your KVM host (dom0 for Xen):

#yum install libvirt -y

2. Make sure virsh utility is installed:

#virsh --version

2.0.0

3. Login to the Guest OS.

4. Let the VM wait before rebooting on kernel panic:

#sysctl kernel.panic=10000 (number of seconds to wait)

5. Wait until the Guest OS is crashed.

6. Gather VM dump with virsh:

#virsh dump domain_name --memory-only --format=kdump-zlib

FYI: If your virsh utility doesn’t support --format option, just skip it:

#virsh dump domain_name --memory-only

7.Upload the dump onto the dump server.