On Mon, Mar 17, 2014 at 05:46:04PM -0600, Jim Fehlig wrote: > I received a report about an odd use case of /etc/libvirt/<driver>/ > config files, and would like to hear some opinions about it. The user > "preps" a host by mounting a remote fs containing VM images and config, > creates links in /etc/libvirt/<driver>/dom.xml to > /mnt-point/whatever/dom.xml, and starts libvirtd. All is well until > there is a need to modify the VM config (e.g. virsh setmaxmem ... > --config), at which point libvirt replaces the link with a file > containing the new config, instead of updating the contents of the > linked file. FWIW the reason why that happens is because when we write the new XML we don't simply re-write the existing XML file. That would be unsafe, because in the event of host crash you could end up with a zero length or partially written XML file. Instead we write to a temporary file and then issue a rename() syscall which atomically replaces the old with new. Regards, Daniel -- |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| |: http://libvirt.org -o- http://virt-manager.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: http://entangle-photo.org -o- http://live.gnome.org/gtk-vnc :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list