The postcopy-recover migration state in QEMU means a connection for the migration stream was established. Depending on the schedulers on both hosts a relative timing of the corresponding MIGRATION event on the source host and the destination host may differ. Specifically it's possible that the source sees postcopy-recover while the destination is still in postcopy-paused. Currently the Perform phase on the source host ends when we get postcopy-recover event and the Finish phase on the destination host is called. If this is fast enough we can still see postcopy-paused state when the Finish phase starts waiting for migration to complete. This is interpreted as a failure and reported back to the caller. Even though the recovery may actually start just a few moments later. To avoid this race we now don't consider post-copy migration active in postcopy-recover state and keep waiting for postcopy-active event (in the success path). Thus the Finish phase is entered only after the migration switches to postcopy-active. In this state QEMU guarantees the destination already switched at least to postcopy-recover and we won't be confused be seeing an old postcopy-failed state. https://issues.redhat.com/browse/RHEL-73085 Signed-off-by: Jiri Denemark <jdenemar@redhat.com> Reviewed-by: Michal Privoznik <mprivozn@redhat.com
Libvirt API for virtualization
Libvirt provides a portable, long term stable C API for managing the virtualization technologies provided by many operating systems. It includes support for QEMU, KVM, Xen, LXC, bhyve, Virtuozzo, VMware vCenter and ESX, VMware Desktop, Hyper-V, VirtualBox and the POWER Hypervisor.
For some of these hypervisors, it provides a stateful management daemon which runs on the virtualization host allowing access to the API both by non-privileged local users and remote users.
Layered packages provide bindings of the libvirt C API into other languages including Python, Perl, PHP, Go, Java, OCaml, as well as mappings into object systems such as GObject, CIM and SNMP.
Further information about the libvirt project can be found on the website:
License
The libvirt C API is distributed under the terms of GNU Lesser General Public License, version 2.1 (or later). Some parts of the code that are not part of the C library may have the more restrictive GNU General Public License, version 2.0 (or later). See the files COPYING.LESSER
and COPYING
for full license terms & conditions.
Installation
Instructions on building and installing libvirt can be found on the website:
https://libvirt.org/compiling.html
Contributing
The libvirt project welcomes contributions in many ways. For most components the best way to contribute is to send patches to the primary development mailing list. Further guidance on this can be found on the website:
https://libvirt.org/contribute.html
Contact
The libvirt project has two primary mailing lists:
- users@lists.libvirt.org (for user discussions)
- devel@lists.libvirt.org (for development only)
Further details on contacting the project are available on the website: