Comment 10 for bug 1796981

Chris, yes those are the correct text to look for in the log files. But you said you had none of those entries, so that means there was no error encountered while the libvirt driver was getting block stats. It implies that the domain.blockStats() libvirt python binding returned None, but I don't know why it would do that. This is the method that's called at the lower level:

https://libvirt.org/html/libvirt-libvirt-domain.html#virDomainBlockStats