The Canada .pbf is 2Gb, so a Canadian.osm will be really huge (25Gb or so at a rough guess?). Are you sure that you’re not just running out of disk space? Will whatever you’re using handle .pbf files?
If you want to see if the .osm that you’ve got use “tail” on it - I don’t have one here to try but I’d expect that you’d see the closing XML “” if it’s complete. If you don’t have “tail” available in your operating system (e.g. Windows) perhaps have a look at using the one from http://unxutils.sourceforge.net/ .