traces by hand (as text files) or turn them into graphical
visualizations.
+IMPORTANT NOTE: This is not upstream (in qemu) nor integrated into
+libguestfs. We should probably be using the 'blktrace' command
+instead, or if that is not suitable, get a more reliable and useful
+trace mechanism added to qemu (the current patch is not suitable for
+upstreaming).
+
The *.qtr files are qemu trace files, produced using the unofficial
qemu patch in the current directory.