On Wed, Sep 24, 2014 at 12:58:06PM -0700, Roman Podoliaka wrote: > Hi Joe, > > Tools like Pumphouse [1] (migrates workloads, e.g. instances, between > two OpenStack clouds) would benefit from supporting this (Pumphouse > would be able to replicate user instances in a new cloud up to their > UUIDs). > > Are there any known gotchas with support of this feature in REST APIs > (in general)? UUIDs must obviously be unique across *all* users' VMs in the cloud, thus this is obviously a risk that the UUID you request is already in use by another user account's VM instance. If people use a sensible random UUID generator this risk is small, but if people decide to use "easy to remember" UUIDs like 000000000-0000-0000-0000-000000001 then the collision risk is large :-) 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 :|