Yes sauerkraut does have a smell to it while fermenting which is a good thing and means that the sauerkraut is fermenting properly.
When sauerkraut is fermenting it will have a pungent and strong odor.
The cabbage contains sulfur compounds which causes a pungent strong odor that can be off putting but it is a good thing when the sauerkraut is fermenting.
If you're not getting a smell from the sauerkraut then it is likely not fermenting properly but when you get a strong pungent odor while the sauerkraut is fermenting then you're doing it correctly.
To get the best quality homemade sauerkraut you should ferment the sauerkraut for at least 20 days but you can go a bit longer if you want too.