mirror of
https://gitlab.com/libvirt/libvirt.git
synced 2025-02-22 19:32:19 +00:00
fbe7a88373
When the XenStore tdb lives persistently and is not cleared between host reboots, Xend (version 3.4 and 4.1) re-creates the domain information located in XenStore below /vm/$UUID. (According to the xen-3.2-commit hg265950e3df69 to fix a problem when locally migrating a domain to the host itself.) When doing so a version number is added to the UUID separated by one dash, which confuses xenStoreDomainIntroduced(): It iterates over all domains and tries to lookup all inactive domains using xenStoreDomainGetUUID(), which fails if the running domain is renamed: virUUIDParse() fails to parse the versioned UUID and the domain is flagged as missing. When this happens the function delays .2s and re-tries 20 times again, multiplied by the number of renamed VMs. 14:48:38.878: 4285: debug : xenStoreDomainIntroduced:1354 : Some domains were missing, trying again This adds a significant delay: # time virsh list >/dev/null real 0m6.529s # xenstore-list /vm 00000000-0000-0000-0000-000000000000 00000000-0000-0000-0000-000000000000-1 00000000-0000-0000-0000-000000000000-2 00000000-0000-0000-0000-000000000000-3 00000000-0000-0000-0000-000000000000-4 00000000-0000-0000-0000-000000000000-5 7c06121e-90c3-93d4-0126-50481d485cca 00000000-0000-0000-0000-000000000000-6 00000000-0000-0000-0000-000000000000-7 144ad19d-dfb4-2f80-8045-09196bb8784f 00000000-0000-0000-0000-000000000000-8 144ad19d-dfb4-2f80-8045-09196bb8784f-1 00000000-0000-0000-0000-000000000000-9 00000000-0000-0000-0000-000000000000-10 00000000-0000-0000-0000-000000000000-11 00000000-0000-0000-0000-000000000000-12 00000000-0000-0000-0000-000000000000-13 00000000-0000-0000-0000-000000000000-14 144ad19d-dfb4-2f80-8045-09196bb8784f-2 00000000-0000-0000-0000-000000000000-15 144ad19d-dfb4-2f80-8045-09196bb8784f-3 00000000-0000-0000-0000-000000000000-16 The patch adds truncation of the UUID as read from the XenStore path before passing it to virUUIDParse(). The same issue is reported at <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=666135> Signed-off-by: Philipp Hahn <hahn@univention.de>
LibVirt : simple API for virtualization
Libvirt is a C toolkit to interact with the virtualization capabilities
of recent versions of Linux (and other OSes). It is free software
available under the GNU Lesser General Public License. Virtualization of
the Linux Operating System means the ability to run multiple instances of
Operating Systems concurrently on a single hardware system where the basic
resources are driven by a Linux instance. The library aim at providing
long term stable C API initially for the Xen paravirtualization but
should be able to integrate other virtualization mechanisms if needed.
Daniel Veillard <veillard@redhat.com>