14.5.22. Creating a Dump File of a Domain's Core

Sometimes it is necessary (especially in the cases of troubleshooting), to create a dump file containing the core of the domain so that it can be analyzed. In this case, running virsh dump domain corefilepath --bypass-cache --live |--crash |--reset --verbose --memory-only dumps the domain core to a file specified by the corefilepath Note that some hypervisors may gave restrictions on this action and may require the user to manually ensure proper permissions on the file and path specified in the corefilepath parameter. This command is supported with SR-IOV devices as well as other passthrough devices. The following options are supported and have the following effect:
  • --bypass-cache the file saved will not contain the file system cache. Note that selecting this option may slow down dump operation.
  • --live will save the file as the domain continues to run and will not pause or stop the domain.
  • --crash puts the domain in a crashed status rather than leaving it in a paused state while the dump file is saved.
  • --reset once the dump file is successfully saved, the domain will reset.
  • --verbose displays the progress of the dump process
  • --memory-only the only information that will be saved in the dump file will be the domain's memory and CPU common register file.
Note that the entire process can be monitored using the domjobinfo command and can be canceled using the domjobabort command.