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Virtualization Guide
  1. Preface
  2. I Introduction
    1. 1 Virtualization technology
    2. 2 Virtualization scenarios
    3. 3 Introduction to Xen virtualization
    4. 4 Introduction to KVM virtualization
    5. 5 Virtualization tools
    6. 6 Installation of virtualization components
  3. II Managing virtual machines with libvirt
    1. 7 Starting and stopping libvirtd
    2. 8 Preparing the VM Host Server
    3. 9 Guest installation
    4. 10 Basic VM Guest management
    5. 11 Connecting and authorizing
    6. 12 Advanced storage topics
    7. 13 Configuring virtual machines with Virtual Machine Manager
    8. 14 Configuring virtual machines with virsh
    9. 15 Xen to KVM migration guide
  4. III Hypervisor-independent features
    1. 16 Disk cache modes
    2. 17 VM Guest clock settings
    3. 18 libguestfs
    4. 19 QEMU guest agent
    5. 20 Software TPM emulator
    6. 21 Creating crash dumps of a VM Guest
  5. IV Managing virtual machines with Xen
    1. 22 Setting up a virtual machine host
    2. 23 Virtual networking
    3. 24 Managing a virtualization environment
    4. 25 Block devices in Xen
    5. 26 Virtualization: configuration options and settings
    6. 27 Administrative tasks
    7. 28 XenStore: configuration database shared between domains
    8. 29 Xen as a high-availability virtualization host
    9. 30 Xen: converting a paravirtual (PV) guest into a fully virtual (FV/HVM) guest
  6. V Managing virtual machines with QEMU
    1. 31 QEMU overview
    2. 32 Setting up a KVM VM Host Server
    3. 33 Guest installation
    4. 34 Running virtual machines with qemu-system-ARCH
    5. 35 Virtual machine administration using QEMU monitor
  7. VI Troubleshooting
    1. 36 Integrated help and package documentation
    2. 37 Gathering system information and logs
  8. Glossary
  9. A Configuring GPU Pass-Through for NVIDIA cards
  10. B GNU licenses
Applies to openSUSE Leap 15.4

21 Creating crash dumps of a VM Guest Edit source

21.1 Introduction Edit source

Whenever a VM crashes, it is useful to collect a core dump of the VM memory for debugging and analysis. For physical machines, Kexec and Kdump takes care of collecting crash dumps. For virtual machines, it depends whether the guest is fully virtualized (FV) or paravirtualized (PV).

21.2 Creating crash dumps for fully virtualized machines Edit source

To view crash dumps for FV machines, use the same procedures as for physical machines—Kexec and Kdump.

21.3 Creating crash dumps for paravirtualized machines Edit source

Unlike with FVs, Kexec/Kdump does not work in paravirtualized machines. Crash dumps of PV guests must be performed by the host tool stack. If using the xl tool stack for Xen domUs, the xl dump-core command will produce the dump. For libvirt-based VM Guests, the virsh dump command provides the same functionality.

You can configure automatic collection of a core dump with the on_crash setting in the configuration of the VM Guest. This setting tells the host tool stack what to do if the VM Guest encounters a crash. The default in both xl and libvirt is destroy. Useful options for automatically collecting a core dump are coredump-destroy and coredump-restart.

21.4 Additional information Edit source

  • The difference between fully virtualized and paravirtualized virtual machines is described in Section 1.3, “Virtualization modes”.

  • Detailed information about Kexec/Kdump mechanism is included in Book “System Analysis and Tuning Guide”, Chapter 18 “Kexec and Kdump”.

  • Refer to the xl.cfg manual page (man 5 xl.cfg) for more information on the xl configuration syntax.

  • Refer to https://libvirt.org/formatdomain.html#events-configuration for details about the libvirt XML settings.

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